459 - Graph Connectivity

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dumle
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Posts: 3
Joined: Mon Sep 16, 2013 9:23 pm

Re: 459 - Graph Connectivity - WA

Post by dumle » Tue Sep 17, 2013 11:18 pm

Ok, so my second for-loop was flawed since it only checked vectors right beside eachother.
Fixed it with a nested for-loop so it passed the test above, still WA tho :/

Code: Select all

ac
Last edited by dumle on Thu Sep 19, 2013 10:21 pm, edited 1 time in total.

brianfry713
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Location: San Jose, CA, USA

Re: 459 - Graph Connectivity - WA

Post by brianfry713 » Thu Sep 19, 2013 12:44 am

Rewrite your code.

I solved it using DFS.
Check input and AC output for thousands of problems on uDebug!

brianfry713
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Location: San Jose, CA, USA

Re: 459 - Graph Connectivity - WA

Post by brianfry713 » Sat Sep 21, 2013 1:09 am

Input:

Code: Select all

2

A

B
Output should be:

Code: Select all

1

2
Check input and AC output for thousands of problems on uDebug!

Skynet094
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Posts: 3
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Re: 459 - Graph Connectivity - WA

Post by Skynet094 » Wed Nov 13, 2013 5:27 am

#include<cstdio>
#include<iostream>
#include<string>
#include<vector>
#include<cstring>
using namespace std;
#define MAX 500

int parent[MAX];

int find_r(int a);
void make_set(int N);
void Union(int a, int b);
int disjoint_count(int n);



void make_set(int N)
{
for(int i=1;i<=N;i++)
parent=i;
}


void Union(int a, int b)
{

int u=find_r(a);
int v=find_r(b);

if(u==v)
return;
else
{parent[v]=u;

}

}

int find_r(int a)
{
if(parent[a]==a)
return a;
else
{
return parent[a]=find_r(parent[a]);


}

}


int disjoint_count(int n)
{


int par[MAX];

int iter=0;
int flag;

for(int i=1;i<=n;i++)
{
flag=0;
int temp=find_r(i);

for(int j=iter+1;j>=1;j--)
if(par[j]==temp)
{
flag=1;
break;
}

if(flag==0)
{
par[++iter]=temp;

}

}



return iter;


}



int main(void)
{

int testcase;
cin>>testcase;
fflush(stdin);

int lol=testcase;
char ch;
string line;
vector<string>container;

while(testcase--)
{
memset(parent,0,sizeof(parent));

getline(cin,line);
cin>>ch;
fflush(stdin);

// cout<<ch<<endl;

make_set(ch-64);

getline(cin,line);
//cout<<line<<endl;

while(!line.empty())
{
container.push_back(line);
getline(cin,line);
}

for(int i=0;i<container.size();i++)
{
Union(container[0]-64,container[1]-64);
}

int _count=disjoint_count(ch-64);

cout<<_count<<endl;
if(testcase!=1)
cout<<"\n"<<endl;


}


return 0;
}
//Can someone tell me what to change, the code gives correct output in my compiler

shariftech
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Posts: 1
Joined: Wed Nov 13, 2013 10:05 am

Re: 459 - Graph Connectivity - TLE

Post by shariftech » Wed Nov 13, 2013 10:15 am

Getting TLE ... I think it occurs because of ugly input ... But can not understand where is my fault ...

Code: Select all

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cctype>
#define MAX 5000

using namespace std;
int par[1000];
int flag;
int node;
void makeset (int n)
{

    for(int i=1; i<=n; i++)
        par[i] = i;
}

int find (int a)
{

    if(par[a]==a) return a;
    else
        return par[a] = find(par[a]);
}

void makeunion(int a, int b)
{

    int u = find(a);
    int v = find(b);

    if(u!=v){
            par[u] = v;
    }
}
int char2int (char c)
{

    return c-'A'+1;
}

void input()
{

    char ch[5];
    while(gets(ch)&&ch[0]){

        int ln;
        ln = strlen(ch);
        if(ln==1){
            node = char2int(ch[0]);
            makeset(node);
        }
        else{
            int a = char2int(ch[0]);
           int b = char2int(ch[1]);
            makeunion(a,b);
        }

    }
}
void free ()
{
    for(int i=0; i<=node; i++){
        par[i]=0;
    }
    node = 0;
}

int main()
{
    int n,i,j,a,b,cnt;

    scanf("%d%*c%*c",&n);
    flag = 0;

    while(n--){
        input();
        cnt = 0;
        for(i=1; i<=node; i++){
                if(par[i]==i)
                    cnt++;
        }
        if(flag==0)
            flag = 1;
        else
        cout<<endl;
        cout<<cnt;
        free();
    }



    return 0;
}

brianfry713
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Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

Re: 459 - Graph Connectivity - WA

Post by brianfry713 » Thu Nov 14, 2013 3:29 am

Skynet094, don't use fflush(stdin);
Check input and AC output for thousands of problems on uDebug!

brianfry713
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Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

Re: 459 - Graph Connectivity - WA

Post by brianfry713 » Thu Nov 14, 2013 3:31 am

shariftech, The outputs of two consecutive cases will be separated by a blank line. Always print a newline char at the end of the last line.
Check input and AC output for thousands of problems on uDebug!

walking_hell
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Posts: 14
Joined: Tue Sep 24, 2013 4:35 pm

uva 459

Post by walking_hell » Wed Nov 20, 2013 7:38 pm

thanxxxxx....got accepted
Last edited by walking_hell on Thu Nov 21, 2013 5:21 pm, edited 1 time in total.

brianfry713
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Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

Re: uva 459

Post by brianfry713 » Wed Nov 20, 2013 10:00 pm

Try input:

Code: Select all

1

Z
AC
AD
AE
AI
AL
AM
AN
AO
AQ
AS
AV
AW
AX
AY
BF
BH
BJ
BK
BL
BM
BN
BO
BP
BQ
BR
BU
BV
BW
BY
CE
CG
CI
CJ
CM
CP
CT
CU
CV
CY
DF
DG
DJ
DK
DL
DM
DN
DO
DQ
DV
DX
EF
EH
EK
EL
EM
EN
EO
ER
ES
ET
EU
EY
EZ
FG
FH
FI
FJ
FM
FN
FO
FP
FR
FU
FW
FY
FZ
GH
GL
GM
GP
GQ
GR
GS
GZ
HI
HJ
HK
HL
HQ
HR
HS
HV
HW
HY
IK
IM
IO
IP
IR
IU
IV
IX
IY
IZ
JK
JL
JM
JN
JR
JW
KM
KO
KP
KR
KS
KX
KY
KZ
LO
LP
LQ
LR
LY
MN
MO
MP
MR
MT
MU
MV
MX
MZ
NP
NR
NT
NV
NY
OQ
OV
OW
OX
PR
PS
PT
PV
PW
PX
PY
PZ
QR
QT
QV
QY
RT
RU
RW
RY
RZ
ST
SV
SZ
TX
TY
TZ
UW
UY
UZ
VW
WZ
XY
XZ
Your code is throwing a seg fault
Check input and AC output for thousands of problems on uDebug!

shuvokr
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Posts: 66
Joined: Tue Oct 02, 2012 8:16 pm
Location: Bangladesh

Re: uva 459

Post by shuvokr » Thu Nov 21, 2013 8:13 pm

@raihan.sust try this input:

Code: Select all

1

E
AB

Code: Select all

so the graph is
A -> B
C
D
E
So what should be the result

Code: Select all

enjoying life ..... 

RookiE3
New poster
Posts: 16
Joined: Tue Feb 18, 2014 7:59 pm

Re: uva 459

Post by RookiE3 » Wed Mar 26, 2014 7:21 pm

Please somebody help me with this code. I am getting TLE... It gives correct answers I think

Code: Select all

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

int par[30];

void makeset(int n)
{
    par[n] = n;
}

int findpar(int n)
{
    if(par[n] == n)
        return n;
    else
        return (par[n] = findpar(par[n]));
}

void Union(int a, int b)
{
    int para = findpar(a);
    int parb = findpar(b);

    if(para != parb)
    {
        par[parb] = para;
    }
}

int main()
{
    freopen("in.txt", "r", stdin);

    set<int> Sets;
    int num, t;
    char largest, a, b;

    scanf("%d", &t);
    getchar();
    getchar();
    while(t--)
    {
        Sets.clear();
        num = 0;
        scanf("%c", &largest);
        if(largest == '\n')
            break;
        getchar();

        for(char i='A'; i<=largest; i++)
            makeset(i-64);

        while(true)
        {
            a = getchar();
            if(a != '\n')
                b = getchar();
            else
                break;
            Union(a-64, b-64);
            getchar();
        }
        for(char i='A'; i<=largest; i++)
        {
            Sets.insert(findpar(i-64));
        }
        printf("%d\n\n", Sets.size());
    }
    return 0;
}


brianfry713
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Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

Re: uva 459

Post by brianfry713 » Wed Mar 26, 2014 8:30 pm

Don't read from a file.
Check input and AC output for thousands of problems on uDebug!

RookiE3
New poster
Posts: 16
Joined: Tue Feb 18, 2014 7:59 pm

Re: uva 459

Post by RookiE3 » Tue Apr 01, 2014 8:20 pm

Please somebody help me. I am getting TLE in this problem...

Code: Select all

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

int par[30];
int num;

void makeset(int n)
{
    par[n] = n;
}

int findpar(int n)
{
    if(par[n] == n)
        return n;
    else
        return (par[n] = findpar(n));
}

void Union(int a, int b)
{
    int para = findpar(a);
    int parb = findpar(b);

    if(para != parb)
    {
        par[parb] = para;
        num++;
    }
}

int main()
{
    int t;
    char largest;
    char a, b;
    scanf("%d", &t);
    getchar();
    while(t--)
    {
        num = 0;
        scanf("%c", &largest);
        getchar();
        for(char i='A'; i<=largest; i++)
            makeset(i-64);

        while(true)
        {
            a = getchar();
            if(a != '\n')
                b = getchar();
            else
                break;
            cout << a << " " << b;
            Union(a-64, b-64);
            getchar();
        }

        printf("%d\n", num);
    }
    return 0;
}

brianfry713
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Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

Re: uva 459

Post by brianfry713 » Tue Apr 01, 2014 9:28 pm

Try running your code on the sample input.
Check input and AC output for thousands of problems on uDebug!

mgavin2
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Posts: 43
Joined: Sat Jul 28, 2012 6:29 pm

Re: 459 - Graph Connectivity

Post by mgavin2 » Wed Oct 08, 2014 6:30 pm

I'm gonna throw my code up here because I'm not exactly sure what I'm doing wrong for this problem.
I'm new to trying to solve graph problems (that weren't implicit graphs modeled as ascii maps for like floodfill problems), so I'm trying to model this problem input as an adjacency matrix... and I think I'm traversing it right.

Thanks for your code review and insights that'll help me on other graph problems :).

Code: Select all

AC

thank bfry :>
Last edited by mgavin2 on Thu Oct 09, 2014 6:49 am, edited 1 time in total.
all that matters is AC

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