## 11402 - Ahoy, Pirates!

All about problems in Volume 114. If there is a thread about your problem, please use it. If not, create one with its number in the subject.

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AmirAz
New poster
Posts: 8
Joined: Tue May 20, 2014 12:34 pm

### Re: 11402 - Ahoy, Pirates

I wrote the program based on what is on the link. 'S' is ready to answer 'I' is reverse 'E' is clear 'F' is set. the program now doesn't give the proper answer, can you tell me where am I wrong.

Code: Select all

``````#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <cstdio>
#include <string>
#include <cstring>
#include <set>
#include <algorithm>
#include <ctype.h>
#include <map>
#include <vector>
#include <stack>
#include <climits>
#include <functional>
#include <sstream>
#include <math.h>

using namespace std;
#define lli long long int
#define llu long long unsigned
#define ii pair<int, int>
#define vii vector<ii>
#define vi vector<int>
#define log2(n) log10(n) / log10(2)
#define getMid(a, b) floor(a + b) /2;
#define mii map<int,int>

class SegmentTree{

public:
int tree_len, *tree; int *source; char *stat; int size;
int build(int p, int s, int e){
stat[p] = 'S';
if (s == e)
return tree[p] = (source[s]);
int mid = getMid(s, e);
return tree[p]  = build((p<<1), s, mid) + build((p<<1) + 1, mid + 1, e);
}
SegmentTree(int *ex , int n){
size  = n;
int h = ceil(log2(size));
source = new int [n]; stat = new char [n];
for (int i = 0; i < n; i++)
source[i] = ex[i];
tree_len = 2 * pow(2, h);
tree = new int[tree_len+1];
build(1, 0, size-1);
}

void rUpdate(int p, int s, int e, int qs, int qe, char com){
if (s > qe || e < qs)
return;

if (s == e){
if (com == 'I') tree[p] =(tree[p] == 1? 0 : 1);
else if (com == 'F') tree[p] = 1;
else source[s] = tree[p] = 0;
stat[p] = 'S';
}
else{
int mid = getMid(s, e);
if (e <= qe && s >= qs){
stat[p] = com; int range = e -s + 1;
if (stat[p] == 'F') tree[p] = range;
else if (stat[p] == 'E') tree[p] = 0;
else if (stat[p] == 'I') tree[p] = range - tree[p];
stat[p<<1] = stat[(p<<1) + 1] = stat[p];
return;
}
rUpdate ((p<<1), s, mid, qs, qe, com);
rUpdate ((p<<1)+ 1, mid+1, e, qs, qe, com);
tree[p] = tree[(p<<1)] + tree[(p<<1)+1];
}

}

int getSum(int p, int s, int e, int i, int j){
if (s > j || e < i)
return 0;
if (s == e)
return tree[p];

if ( s >= i && e <= j)
{
if (stat[p] == 'S')
return tree[p];
int range = e - s + 1;
if (stat[p] == 'F') tree[p] = range;
else if (stat[p] == 'E') tree[p] = 0;
else if (stat[p] == 'I') tree[p] = range - tree[p];

stat[(p<<1)+1] = stat[p<<1] = stat[p];
stat[p] = 'S';
return tree[p];
}
int mid = getMid(s, e);
return getSum((p<<1), s, mid, i, j) + getSum((p<<1)+1, mid + 1, e, i, j);
}

};

int main(){
int *source = new int[1024001];
int T; cin >> T;

for (int tc = 1; tc <= T; tc++){
int m; cin >> m;
int size = 0;
for (int i = 0; i < m; i++)
{
int time; cin >> time;
string orig; cin >> orig;
for (int j = 0; j < time; j++)
for (int k = 0; k < orig.size(); k++)
source[size++] = orig[k] - '0';

}
SegmentTree st(source, size);
cout << "Case " << tc << ":\n";
int q; cin >> q; int god = 0;
for (int i = 0; i < q; i++){
int s, e; char a;
cin >> a >> s >> e;
if (a != 'S') st.rUpdate(1, 0, st.size -1, s, e, a);
else cout << "Q"<<++god << ": " <<st.getSum(1, 0, st.size -1, s, e) << "\n";

}

}
delete [] source;
}``````

lbv
Experienced poster
Posts: 128
Joined: Tue Nov 29, 2011 8:40 am

### Re: 11402 - Ahoy, Pirates

AmirAz wrote:I wrote the program based on what is on the link. (..) the program now doesn't give the proper answer, can you tell me where am I wrong.
For now, I can see a couple of things that seem a little wonky:

Inside the segment tree, I think the stat member should be of size tree_len and not n. Being shorter than needed could result in an array overflow, which is probably the cause of the most notable errors.

While on the subject of memory, every piece of memory you reserve with new should be freed with delete. You never free all that memory you reserve every time a segment tree is created. As a personal recommendation, I'd suggest to never do dynamic memory allocation inside programs for competitive programming. It usually adds a lot of complexity and subtle errors that are hard to catch for little (if any) gain. Maybe consider using C++ containers like vectors.

Also, try to avoid using floating point calculations unnecesarily. For example the getMid doesn't really need to use floor because you're dealing with integers.

There may be other issues, but you can start with these.

AmirAz
New poster
Posts: 8
Joined: Tue May 20, 2014 12:34 pm

### Re: 11402 - Ahoy, Pirates

Hi lbv you are undoubtedly more than experienced. I got AC, tnx! Here is my working segment tree:

Code: Select all

``````class SegmentTree{

public:

int tree_len, *tree; bool *source; short *situ; int size;
int build(int p, int s, int e){
situ[p] = S;
if (s == e)
return tree[p] = (source[s]?1:0);
int mid = getMid(s, e);
return tree[p]  = build((p<<1), s, mid) + build((p<<1) + 1, mid + 1, e);
}
SegmentTree(bool *ex , int n){
size  = n;
int h = ceil(log2(size)) + 1;

source = ex;
tree_len = 2 * pow(2, h);
tree = new int[tree_len+1];
situ = new short [tree_len+1];
build(1, 0, size-1);
}
~SegmentTree(){
delete [] tree;
delete [] situ;
}
void update(int p, int s, int e){
if (situ[p] == S) return;
if (situ[p] == F)
tree[p] = e -s + 1;
else if (situ[p] == E)
tree[p] = 0;
else if (situ[p] == I)
tree[p] = (e - s + 1) - tree[p];

if (s != e){
if (situ[p] == F || situ[p] == E)
situ[_left(p)] = situ[_right(p)] = situ[p];
else
situ[_left(p)] = flip(situ[_left(p)]), situ[_right(p)] = flip(situ[_right(p)]);

}
situ[p] = S;
}

short flip(short v){
if (v == I) return S;
if (v == F) return E;
if (v == E) return F;
return I;
}

void rUpdate(int p, int s, int e, int qs, int qe, short com){
update (p, s, e);
if (s > qe || e < qs) return;
if (s == e){
switch(com){
case I : tree[p] = 1 - tree[p]; break;
case F : tree[p] = 1; break;
case E : tree[p] = 0; break;
}

return;
}

int mid = getMid(s, e);
if (s >= qs && e <= qe){
switch(com){
case F :{
tree[p] = e- s + 1;
situ [_left(p)] = situ[_right(p)] = com;
break;
}
case I :{
tree[p] = (e -s + 1) - tree[p];
situ[_left(p)] = flip(situ[_left(p)]);
situ[_right(p)] = flip(situ[_right(p)]);
break;
}
case E :{
tree[p] = 0;
situ [_left(p)] = situ[_right(p)] = com;
break;
}
}

return;

}

rUpdate (_left(p), s, mid, qs, qe, com);
rUpdate (_right(p), mid + 1, e, qs, qe, com);
tree[p] = tree[_left(p)] + tree[_right(p)];
}

int getSum(int p, int s, int e, int i, int j){
if (e < i || s > j) return 0;
update (p, s, e);
if (s >= i && e <= j) return tree[p];
int mid = getMid(s, e);
return getSum(_left(p), s, mid, i, j) + getSum(_right(p), mid + 1, e, i, j);
}

};``````

prav90
New poster
Posts: 1
Joined: Sun Aug 24, 2014 9:31 pm

### 11402 - Ahoy Pirates Java

Hi All,

I tried solving this problem using lazy updates in Segment tree. I get TLE in Java. Can somebody provide any hints on getting AC using Java. Does it need a fast IO or is my implementation wrong? I have been working on this for a while and am stuck at this point.

My Code :

Code: Select all

``````import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;

// each node in the Segment Tree
// stores the number of nodes in its subtree
// number of ones in its subtree
// magician cast type for lazy updates
class Node {
int length, ones;
char qtype;
}

class SegmentTreePirates {
Node [] st;
int n;
SegmentTreePirates(StringBuilder arr, int n) {
this.n = n;
st = new Node[4*n];
// we ignore index 0 in the segment tree
for(int i = 1; i < 4*n; i++)
st[i] = new Node();
build(1, 0, n-1, arr);
}

/* return right and left childs of the given index */
private int left(int i) { return i<<1; }
private int right(int i) { return (i<<1)+1; }

// construct the segment tree from the given array recursively
private void build(int index, int l, int r, StringBuilder arr) {
// check if we have reached a leaf node
if(l == r) {
st[index].length = 1;
st[index].qtype = 9999; // flag value indicating no updates
if(arr.charAt(l) == '1') st[index].ones = 1;
else st[index].ones = 0;
}
else { // build the tree recursively
int mid = (l+r)/2;
build(left(index), l, mid, arr);
build(right(index), mid + 1, r, arr);
st[index].qtype = 9999;
st[index].ones = st[left(index)].ones + st[right(index)].ones;
st[index].length = (r-l+1);
}
}

public void update(int l, int r, char type) {
update(1, 0, n-1, l, r, type);
}

private void changeType(int i, char type) {
if(type == 'I') {
switch(st[i].qtype)
{
case 'F' :
st[i].qtype = 'E';
break;
case 'E' :
st[i].qtype = 'F';
break;
case 'I' :
st[i].qtype = 9999;
break;
case 9999 :
st[i].qtype = 'I';
break;

}
}
else {
st[i].qtype = type;
}
}
// performs the update operation based on the qtype
private void update( int index ) {
switch(st[index].qtype) {
case 'F' :
st[index].ones = st[index].length;
break;
case 'E' :
st[index].ones = 0;
break;
case 'I' :
st[index].ones = st[index].length - st[index].ones;
}
}

private void update(int index, int l, int r, int i, int j, char type) {
// if tree range is within the update range
if(l >= i && r <= j)
changeType(index, type);
if(st[index].qtype != 9999) {
update(index);
// marks its children as lazy if it's not the leaf node
if(l != r) {
//System.out.println("Index : " + index +" l : " + l + " r : " +r);
changeType(left(index), st[index].qtype);
changeType(right(index), st[index].qtype);
}
// unset the lazy update qtype
st[index].qtype = 9999;
}
// within the range
if(l >= i && r <= j) return;
// return if outside the range
else if(l > j || r < i) return;
else {
int mid = (l+r)/2;
update(left(index), l, mid, i, j, type);
update(right(index), mid+1, r, i, j, type);
st[index].ones = st[left(index)].ones + st[right(index)].ones;
}
}

public int query(int i, int j) {
return query(1, 0, n-1, i, j);
}

private int query(int index, int l, int r, int i, int j) {
//System.out.println("Index : " + index +" l : " + l + " r : " +r);
if(st[index].qtype != 9999) {
update(index);
// marks its children as lazy if it's not the leaf node
if(l != r) {
//System.out.println("Index : " + index +" l : " + l + " r : " +r);
changeType(left(index), st[index].qtype);
changeType(right(index), st[index].qtype);
}
// unset the lazy update qtype
st[index].qtype = 9999;
}
if(l >= i && r <= j) return st[index].ones;
if(l > j || r < i) return 0;
int mid = (l+r)/2;

int ans = query(left(index), l, mid, i, j) + query(right(index), mid+1, r, i, j);
st[index].ones = st[left(index)].ones + st[right(index)].ones;
return ans;
}
}

public class Main {
public static void main(String [] args) throws Exception {
PrintWriter pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
int T = Integer.parseInt(br.readLine());
for(int t = 1; t <= T;t++) {
pw.println("Case "+t+":");
int reps = Integer.parseInt(br.readLine());

StringBuilder ip = new StringBuilder("");
for(int i = 0; i < reps; i++) {
int repCnt = Integer.parseInt(br.readLine());
String repStr = br.readLine();
while(repCnt-- > 0)
ip.append(repStr);
}

SegmentTreePirates st = new SegmentTreePirates(ip, ip.length());
int q = Integer.parseInt(br.readLine());
int godsQ = 0;
while(q-- > 0) {
StringTokenizer sz = new StringTokenizer(br.readLine());
char type = sz.nextToken().charAt(0);
int a = Integer.parseInt(sz.nextToken());
int b = Integer.parseInt(sz.nextToken());

if(type == 'S') {
godsQ++;
pw.println("Q"+godsQ+": "+st.query(a, b));
}
else {
st.update(a, b, type);
}
}
}
pw.close();
}
}
``````
Thanks

Repon kumar Roy
Learning poster
Posts: 96
Joined: Tue Apr 23, 2013 12:54 pm

### Re: 11402 - Ahoy, Pirates!

Getting TLE and
There is some mismatch between brianfry i/o ... But could not find the error

Code: Select all

``````
#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<vector>
#include<map>
#include<queue>
#include<stack>
#include<cstdlib>
#include<algorithm>
#include<set>
#include<iterator>
#include<cassert>
#include <sstream>
using namespace std;

#define MX 1024005
#define ll long long
#define ull unsigned long long
#define mod 1000000007
#define pb push_back
#define pop pop_back

ll x,y,d;

#define ms(ara_name,value) memset(ara_name,value,sizeof(ara_name))
#define gc getchar_unlocked
template<class T > void sc(T &x){
register T c = gc();
x = 0;
for(;(c<48 || c>57);c = gc());
for(;c>47 && c<58;c = gc()) {x = (x<<1) + (x<<3) + c - 48;}
}

template < class T > inline T gcd(T a , T b ) { if(b==0) return a; else return gcd(b, a%b);}
template < class T > inline T lcm(T a , T b ) { return  a*b / gcd(a, b);}
template < class T > inline T extended_euclid_returning_gcd(T a,T b){ T t; if(b==0){d = a;x=1;y=0;} else {extended_euclid_returning_gcd(b, a%b); t=x; x=y;y = t-(a*y/b);}}
template < class T > inline T absolute(T a ) { if(a>0) return a; else return -a;}
template < class T > inline T reverse_num( T a ){ T x=0,tmp = a; while(tmp) { x=10*x+ tmp % 10; tmp/=10;} return x;}
template <class T > inline T big_mod(T base, T power){ T res=1; while (power) { if(power&1){ res*=base; power--;} base =base *base; power/=2;} return res;}

string tmp , manl ;

int T[4*MX];
int lazy[4*MX];

void bulid( int n, int b,int e)
{
if(b==e){
T[n] = (manl[b] == '1' ? 1 : 0);
lazy[n] = 0;
return;
}

int mid = (b + e)/2;
bulid(2*n , b, mid );
bulid(2*n+1, mid +1, e);

T[n] = T[2*n] + T[2*n+1];
lazy[n] = 0;
return;

}

#define UP_SET 99
#define UP_CLR 9999
#define UP_FLIP 99999

void flip (int& n)
{
if(n == UP_CLR)n = UP_SET;
if(n == UP_SET) n = UP_CLR;
if(n == UP_FLIP) n = 0;
if(n== 0) n = UP_FLIP;

return ;
}
void upd (int n,int b,int e ,int i,int j,int val)
{
if(lazy[n]!=0){
if(lazy[n] == UP_SET){
T[n] = (e-b+1);
if(b!=e){
lazy[2* n] = UP_SET;
lazy[2* n + 1] = UP_SET;
}
}
if(lazy[n] == UP_CLR ){
T[n] = 0;
if(b!=e){
lazy[2* n] = UP_CLR;
lazy[2* n + 1] = UP_CLR;
}
}
if(lazy[n] == UP_FLIP) {
T[n] = e-b+1 - T[n];
if(b!=e){
flip(lazy[2*n]);
flip(lazy[2*n+1]);
}
}
lazy[n] = 0;

}

if(b >j || e < i || i > j ) return;
if( b == i && e == j ){

if(val == UP_SET){
T[n] = (e-b+1);
if(b!=e){
lazy[2* n] = UP_SET;
lazy[2* n + 1] = UP_SET;
}
}
if(val== UP_CLR ){
T[n] = 0;
if(b!=e){
lazy[2* n] = UP_CLR;
lazy[2* n + 1] = UP_CLR;

}
}
if(val== UP_FLIP) {
T[n] = e-b+1 - T[n];
if(b!=e){
flip(lazy[2*n]);
flip(lazy[2*n+1]);
}
}
return ;

}

int mid = (b + e)/2;
upd(2*n, b, mid, i, min(j,mid), val);
upd(2*n+1, mid+1, e, max(i,mid + 1), j, val);

T[n] = T[2*n] + T[2*n+1];
return;

}

int que ( int n,int b,int e,int i,int j)
{
if(lazy[n]!=0){
if(lazy[n] == UP_SET){
T[n] = (e-b+1);
if(b!=e){
lazy[2* n] = UP_SET;
lazy[2* n + 1] = UP_SET;
}
}
if(lazy[n] == UP_CLR ){
T[n] = 0;
if(b!=e){
lazy[2* n] = UP_CLR;
lazy[2* n + 1] = UP_CLR;
}
}
if(lazy[n] == UP_FLIP) {
T[n] = e-b+1 - T[n];
if(b!=e){
flip(lazy[2*n]);
flip(lazy[2*n+1]);
}
}
lazy[n] = 0;

}
if(b >j || e < i || i > j ) return 0 ;
if( b == i && e == j ){
return T[n];
}

int mid = ( b  + e )/2;
int p1 = que(n *2, b, mid , i, min(j,mid));
int p2 = que(2*n+1, mid+1, e, max(i,mid+1), j);

return p1+p2;
}

int main()

{

int test,q,cs=0,times,i,j, m ;
char ch;
//for(int i =0 ;  i < 3 *MX; i++) lazy[i] = 0;
//freopen("in.txt", "r", stdin);
sc(test);

while (test--) {

printf("Case %d:\n",++cs);
sc(m);
for (; m--; ) {
sc(times);
string a;
cin>>tmp;
if(tmp.compare("") == 0){
cin >> tmp;
}
while (times--) {
a = a + tmp;
}
manl = manl + a;
}
int sz = (int) manl.length();
cout << manl << endl;
bulid(1, 0, sz-1);

sc(q);
int qno = 0;
while (q--) {
do {
ch = getchar();
} while (ch=='\n'|| ch=='\0' || ch==' ' );

sc(i); sc(j);
if(ch=='F')   upd(1, 0, sz -1 , i, j, UP_SET);
else if(ch=='E')  upd(1, 0, sz-1, i, j, UP_CLR);
else if(ch=='I')   upd(1, 0, sz-1, i, j, UP_FLIP);

else if(ch=='S') {
int res = que(1, 0, sz-1, i, j);
printf("Q%d: %d\n",++qno , res);
}

}
ms(lazy, 0);
ms(T, 0);
manl.clear();
}

return 0;

}

/*
2
2
5
10
2
1000
5
E 0 17
S 0 8
F 0 8
S 0 8
S 0 17
*/
``````

Lim.YuDe
New poster
Posts: 15
Joined: Sat Dec 13, 2014 1:32 pm

### Re: 11402 - Ahoy, Pirates!

Using segment tree with lazy propagation, but still getting TLE.
Any help would be greatly appreciated!

EDIT: edited the code to implement lazy propagation properly, and I have no TLE now but I get RTE instead.. which is weird because I don't get that error when I test my super large input. I must be missing something..

Code: Select all

``````#include <bits/stdc++.h>
using namespace std;

#define REP(a, b, c) \
for (int a = int(b); a < c; a++)

typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<char> vc;

class SegmentTree {
private:
vi st;
vc A, lazy;
int n;
int left (int p) { return p << 1; }
int right (int p) { return (p << 1) + 1; }

void performLazy(int p, int L, int R) {
if (lazy[p] == '\0') return;
if (lazy[p] == 'F') {
st[p] = (R-L+1);
} else if (lazy[p] == 'E') {
st[p] = 0;
} else if (lazy[p] == 'I') {
st[p] = (R-L+1) - st[p];
}
//printf("Performed laziness:%c to L,R:%d,%d; st[%d] = %d\n", lazy[p], L, R, p, st[p]);
if (L != R) {
int l = left(p);
int r = right(p);
//performLazy(left(p), L, (L+R)/2);
//performLazy(right(p), (L+R)/2+1, R);
if (lazy[p] == 'F' || lazy[p] == 'E') {
lazy[l] = lazy[r] = lazy[p];
} else if (lazy[p] == 'I') {
if (lazy[l] == 'I') {
lazy[l] = '\0';
} else if (lazy[l] == 'F') {
lazy[l] = 'E';
} else if (lazy[l] == 'E') {
lazy[l] = 'F';
} else {
lazy[l] = lazy[p];
}
if (lazy[r] == 'I') {
lazy[r] = '\0';
} else if (lazy[r] == 'F') {
lazy[r] = 'E';
} else if (lazy[r] == 'E') {
lazy[r] = 'F';
} else {
lazy[r] = lazy[p];
}
}
}
lazy[p] = '\0';
}
void build (int p, int L, int R) {
if (L > R) return;
if (L == R) { // leaf
st[p] = (A[L] == '1');
//printf("L,R:%d,%d; st[%d] = %d\n", L, R, p, st[p]);
return;
}
build(left(p),  L,          (L+R)/2 );
build(right(p), (L+R)/2+1,  R       );
st[p] = st[left(p)] + st[right(p)];
if (p == 3) {
//printf("st[%d] = st[%d] + st[%d]\n", p, left(p), right(p));
//printf("L,R:%d,%d; st[%d] = %d\n", L, R, p, st[p]);
}
}
int query(int p, int L, int R, int i, int j) {
if (L > R || L > j || R < i) return 0;
performLazy(p, L, R);
if (L >= i && R <= j) {
//printf("Query:L,R:%d,%d, i,j:%d,%d st[%d] = %d\n", L, R, i, j, p, st[p]);
return st[p];
}
int q1 = query(left(p),     L,          (L+R)/2,    i, j);
int q2 = query(right(p),    (L+R)/2+1,  R,          i, j);
//printf("Query:L,R:%d,%d, i,j:%d,%d q1+q2 = %d\n", L, R, i, j, q1+q2);
return q1 + q2;
}
void update(int p, int L, int R, int i, int j, char command) {
performLazy(p, L, R);
if (L > R || L > j || R < i) return;
if (L >= i && R <= j) {
lazy[p] = command;
performLazy(p, L, R);
//printf("Performed command:%c to L,R:%d,%d; st[%d] = %d\n", command, L, R, p, st[p]);
return;
}
update(left(p),     L,          (L+R)/2,    i, j, command);
update(right(p),    (L+R)/2+1,  R,          i, j, command);
st[p] = st[left(p)] + st[right(p)];
//printf("st[%d] = st[%d] + st[%d]\n", p, left(p), right(p));
//printf("L,R:%d,%d; st[%d] = %d\n", L, R, p, st[p]);
}
public:
SegmentTree(const vc& _A) {
A = _A;
n = (int)A.size();
st.assign(3*n, 0);
lazy.assign(3*n, '\0');
build(1, 0, n-1);
}
int query(int i, int j) {
return query(1, 0, n-1, i, j);
}
void update(char command, int a, int b) {
update(1, 0, n-1, a, b, command);
}
};

char line[51] = "000000111111111111";
vc pirates;
int t, m, repeats, q, qNo, a, b;

int main() {
scanf("%d", &t);
REP(caseNo, 1, t+1) {
printf("Case %d:\n", caseNo);

pirates.clear();
scanf("%d", &m);
while (m--) {
scanf("%d %s", &repeats, line);
while (repeats--) {
REP(i, 0, strlen(line)) pirates.push_back(line[i]);
}
}

SegmentTree st(pirates);
//printf("Initial number of buccaneer pirates: %d\n", st.query(0, pirates.size()-1));
scanf("%d", &q);
qNo = 1;
while (q--) {
scanf("%s %d %d", line, &a, &b);
if (line[0] == 'S') {
printf("Q%d: %d\n", qNo++, st.query(a, b));
} else {
st.update(line[0], a, b);
//printf("Updated buccaneer pirates: %d\n", st.query(0, pirates.size()-1));
}
//printf("TEST: query(%d,%d) = %d\n", 999999, 999999, st.query(999999,999999));
//printf("TEST: query(%d,%d) = %d\n", 500000, 999999, st.query(500000,999999));
}
}

return 0;
}
``````

just_yousef
New poster
Posts: 50
Joined: Tue Dec 17, 2013 11:01 pm

### Re: 11402 - Ahoy, Pirates!

hey,
Im getting TLE using segment tree with lazy propagation.
this is my code: http://ideone.com/3QmSt8

asrajmane193
New poster
Posts: 5
Joined: Tue May 26, 2015 9:55 am

### 11402 - Ahoy, Pirates!

I am getting Runtime error for this code. Could someone please help me with that?

http://ideone.com/btRZKZ

asrajmane193
New poster
Posts: 5
Joined: Tue May 26, 2015 9:55 am

### Re: 11402 - Ahoy, Pirates!

I updated my code a little. Here's the updated IDEone. http://ideone.com/r09PKO

asrajmane193
New poster
Posts: 5
Joined: Tue May 26, 2015 9:55 am

### Re: 11402 - Ahoy, Pirates!

Runtime error gone, but now TLE.

I was able to find out the offending statements causing the segmentation fault. Inside "propagate()" function the lines 57, 58, 62, 63, 67, 68 were the culprits - I had not put a condition to end the propagation at the leaf nodes.

Code that's giving TLE is here - http://ideone.com/JjPtwu

It'd be great help if someone could look into it.

bluemmb22
New poster
Posts: 2
Joined: Wed Jul 08, 2015 2:09 pm

### Re: 11402 - Ahoy, Pirates!

asrajmane193 wrote:Runtime error gone, but now TLE.

I was able to find out the offending statements causing the segmentation fault. Inside "propagate()" function the lines 57, 58, 62, 63, 67, 68 were the culprits - I had not put a condition to end the propagation at the leaf nodes.

Code that's giving TLE is here - http://ideone.com/JjPtwu

It'd be great help if someone could look into it.
I Just change your string concatenation and your code got ACCEPTED . strcat have an overhead for creating new array of char and copy both arguments to new one , so you can just do like this :

Code: Select all

``````for (int j = 0; j < r; j++)
for (int k =0 ; k< l ;k++)
desc[n++] = seq[k];
``````

leolleo
New poster
Posts: 1
Joined: Tue Aug 04, 2015 5:29 am

### 11402 - Ahoy, Pirates!

My code passes on all the random test cases generated by the program i've written and the random test case provided by UDebug. Unfortunatelly i'm still getting WA at ~4.334 sec. Can anyone help me?

The code is this: https://ideone.com/KuwNo1

asrajmane193
New poster
Posts: 5
Joined: Tue May 26, 2015 9:55 am

### Re: 11402 - Ahoy, Pirates!

Thanks leolleo, that worked.

mamun4122
New poster
Posts: 3
Joined: Sun Apr 20, 2014 6:06 pm

### Re: 11402 - Ahoy, Pirates!

I am getting wrong answer.I alredy tried test case from udebug.All of my output is correct.can someone give me any test case?

Code: Select all

``````//got AC

``````
Last edited by mamun4122 on Mon Dec 14, 2015 8:40 am, edited 1 time in total.

lusho
New poster
Posts: 4
Joined: Fri Jan 16, 2015 11:41 pm

### 11402 - Ahoy, Pirates!

hello everyone
I am getting TLE but i do not know why?? please could you tell me, what I am doing bad?? I use Segment tree + Lazy Propagation it is my first implementation, thank you everyone, here is my code:

Code: Select all

``````#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
#define MAX 1024600
struct Seg
{
int bucan;
int barba;
char lazy;
};
vector<Seg> ST(MAX*4);
string s,aux;
Seg sum(Seg a,Seg b)
{
Seg n;
n.bucan=a.bucan+b.bucan;
n.barba=a.barba+b.barba;
n.lazy='a';
return n;
}
void Segment_Tree(int nodo,int i,int j)
{
if(i==j)
{
ST[nodo].barba=0;
ST[nodo].bucan=0;
if(s[i]=='1')
ST[nodo].bucan=1;
else
ST[nodo].barba=1;
ST[nodo].lazy='a';
return;
}
int mid=(i+j)>>1;
int izq=nodo<<1;
int der=izq+1;
Segment_Tree(izq,i,mid);
Segment_Tree(der,mid+1,j);
ST[nodo]=sum(ST[izq],ST[der]);
}
void lazy_propagation(int nodo,int a,int b,char opc)
{
if(ST[nodo].lazy=='a' )
{
ST[nodo].lazy=opc;
}
else
{
if(ST[nodo].lazy=='F')
{
ST[nodo].bucan=b-a+1;
ST[nodo].barba=0;
}
else
{
if(ST[nodo].lazy=='E')
{
ST[nodo].barba=b-a+1;
ST[nodo].bucan=0;
}
else
{
if(ST[nodo].lazy=='I')
{
swap(ST[nodo].barba,ST[nodo].bucan);
}
}
}
int mid=(a+b)>>1;
int izq=nodo<<1;
int der=izq+1;
if(a==b)
{
ST[nodo].lazy=opc;
return;
}
lazy_propagation(izq,a,mid,ST[nodo].lazy);
lazy_propagation(der,mid+1,b,ST[nodo].lazy);
ST[nodo].lazy=opc;
}
}
void update(int nodo,int i,int j,int a,int b,char opc)
{
if(ST[nodo].lazy!='a')
{
lazy_propagation(nodo,i,j,ST[nodo].lazy);
ST[nodo].lazy='a';
}
if(i>b || j<a) return;
if(i>=a && j<=b)
{
if(opc=='F')
{
ST[nodo].bucan+=ST[nodo].barba;
ST[nodo].barba=0;
}
else
{
if(opc=='E')
{
ST[nodo].barba+=ST[nodo].bucan;
ST[nodo].bucan=0;
}
else
{
if(opc=='I')
{
swap(ST[nodo].barba,ST[nodo].bucan);
}
}
}
int mid=(i+j)>>1;
int izq=nodo<<1;
int der=izq+1;
if(i==j)
{
return;
}
lazy_propagation(izq,i,mid,opc);
lazy_propagation(der,mid+1,j,opc);
return;
}
int mid=(i+j)>>1;
int izq=nodo<<1;
int der=izq+1;
update(izq,i,mid,a,b,opc);
update(der,mid+1,j,a,b,opc);
ST[nodo].bucan=ST[izq].bucan+ST[der].bucan;
ST[nodo].barba=ST[izq].barba+ST[der].barba;
}
Seg query(int nodo,int i,int j,int a,int b)
{
if(ST[nodo].lazy!='a')
{
lazy_propagation(nodo,i,j,ST[nodo].lazy);
ST[nodo].lazy='a';
}
if(i>=a && j<=b)
return ST[nodo];
int mid=(i+j)>>1;
int izq=nodo<<1;
int der=izq+1;
if(mid>=b)
{
return query(izq,i,mid,a,b);
}
else
{
if(mid+1<=a)
{
return query(der,mid+1,j,a,b);
}
else
{
return sum(query(izq,i,mid,a,b),query(der,mid+1,j,a,b));
}
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int tc,n,veces,que,a,b;
char opc;
cin>>tc;
for(int cp=1;cp<=tc;cp++)
{
s="";
cout<<"Case "<<cp<<":"<<'\n';
cin>>n;
while(n--)
{
cin>>veces;
cin>>aux;
while(veces--)
{
s=s+aux;
}
}
int tam=s.size()-1;
Segment_Tree(1,0,tam);
cin>>que;
int qq=0;
while(que--)
{
cin>>opc>>a>>b;
if(opc=='S')
{
cout<<"Q"<<++qq<<": "<<query(1,0,tam,a,b).bucan<<'\n';
}
else
{
update(1,0,tam,a,b,opc);
}
}
}
return 0;
}``````