Page 4 of 7
Posted: Fri Aug 03, 2007 9:01 am
please !! check the above program , and reply me any test cases , for what my program is wrong.............

Posted: Fri Aug 03, 2007 9:25 am
I can't understand your program well. Could you give a brief explanation of you algorithm ?
Then it well be much more easier to understand and debug.

EDIT : When you post your code, use Code tags.

EDIT : OK. I understood your algorithm. Actually its not correct. I'll make a critical test case.
----
Rio

Posted: Fri Aug 03, 2007 9:57 am
Try this case:

Code: Select all

``````4
3
0 3
1 2
2 3
0
``````
Its obviously bicolorable.
----
Rio

Posted: Fri Aug 03, 2007 10:08 am
Thank you very much .. Rio !!!

### TLE

Posted: Sat Feb 02, 2008 11:14 pm
HI i am having TLE in this prob, can u plz help?

AC

### Re: 10004 - Bicoloring WA

Posted: Mon Sep 22, 2008 10:24 pm

### Re: 10004 - Bicoloring

Posted: Fri Dec 12, 2008 11:47 am
At lastttttttttt GOT ACCEPTED yeyeye:
My Algo:Using like floyd Warshall starting from any first vertex(let A)...color it 1...take all of its adjacent(let B,C) ..(Now i will color all adjacent of A to -1 but i will have to check a condition that after coloring any adjacent of -1 color should not have -1 color)...for that now taking first adjacent(B) check all adjacent of that adjacent(B)..let(D,E) if anyone of D or E has the same color(-1) ..then it means graph is not bicolorable else if all conditions gaot satisfied for all vertex IT is biclorable...

### Re: 10004 - Bicoloring

Posted: Thu Jun 18, 2009 10:44 am
Below is my code. What is the problem

Code: Select all

``````spelling mistake. lol
``````

### Re: 10004 - Bicoloring

Posted: Fri Aug 28, 2009 10:32 pm
Can Sombody help me with my WA!!

Code: Select all

`````` GoT AC --
Dont Forget The dot at the end of your Lines ``````

### Re: 10004 - Bicoloring

Posted: Mon Sep 28, 2009 7:58 am

Code: Select all

``````#include<stdio.h>
#include<queue>
#define  MAX 201
using namespace std;

queue<int>ans;
int n,e;
int path[MAX][MAX];
int col[MAX];

void ini(){
for(int i=0;i<MAX;i++){
for(int j=0;j<MAX;j++)
path[i][j]=0;
col[i]=0;
}

}

int bfs(int u){
int temp;
ans.push(u);
col[u]=1;
while(!ans.empty()){
temp=ans.front();
ans.pop();
for(int i=0;i<n;i++){
if(path[temp][i]==1){
if(col[i]==0){
ans.push(i);
if(col[temp]==1)
col[i]=2;
else
col[i]=1;
}

else if(col[i]==col[temp])
return 0;

}
}
}

return 1;
}

int main(){
freopen("1004.txt","r",stdin);
int a,b,val;
while((scanf("%d",&n)==1)){
if(n==0)
break;
scanf("%d",&e);
ini();
for(int i=0;i<e;i++){
scanf("%d %d",&a,&b);
path[a][b]=path[b][a]=1;
}

if(e>0)
val=bfs(a);
else
val=1;
if(val==0)
printf("NOT BICOLORABLE.\n");
else
printf("BICOLORABLE.\n");

}

return 0;
}``````

### Re: 10004 - Bicoloring

Posted: Wed Oct 14, 2009 8:10 pm
" freopen("1004.txt","r",stdin);
int a,b,val;
while((scanf("%d",&n)==1)){
if(n==0)

"

how can it possible
just comment the line like
// freopen("1004.txt","r",stdin)

### Re: 10004 - Bicoloring

Posted: Sat Aug 14, 2010 8:57 pm
Just got AC on this problem. Some tips:
1. Don't assume that there will be node 0, so don't start your BFS at node 0, use other trick
2.

Code: Select all

``````   Color the starting node ( passed to your BFS func ) with color 1 and enqueue it
mark visited
color it with the opposite of the parent color
enqueue it
else
if parentColor == currentNodeColor
"NOT BICOLORABLE."
"BICOLORABLE."``````

### Re: 10004 - Bicoloring

Posted: Sun Sep 12, 2010 6:11 am
I am asraful .
I tried to solve 10004
But i am getting WA .

Here is my code ...

Code: Select all

``````
#include<stdio.h>

int main(){

int m[203][203],a[203],d[203],p[5],l,e,n,i,j,k;
char c[203];

while(scanf("%d",&n) && n){

for(i=0;i<203;++i)
for(j=0;j<203;++j)
m[i][j]=0;

for(i=0;i<203;++i)
{
a[i]=i;
c[i]='Z';
d[i]=0;
}

for(i=0;i<5;i++)
p[i]=0;

scanf("%d",&e);

for(i=1;i<=e;++i){
scanf("%d%d",&j,&k);
m[j][k]=m[k][j]=1;
}

for(i=0;i<n;++i){
k=0;
for(j=0;j<n;++j)
if(m[i][j]==1)
++k;
d[i]=k;
}

for(i=0;i<n-1;++i)
for(j=i+1;j<n;++j)
if(d[i]<d[j]){
k=d[i];
d[i]=d[j];
d[j]=k;
k=a[i];
a[i]=a[j];
a[j]=k;
}

// /* Coloring *///

l=0;
c[a[0]]='A';

for(i=0;i<n;++i){
if(c[a[i]]=='Z'){
for(j=0;j<n;++j)
if(m[a[i]][j]==1){
if(c[j]!='Z'){
p[c[j]-'A']=1;
}
}

j=0;
for(k=0;k<4;k++){
if(p[k]==0&&j==0){
if(k==0)
c[a[i]]='A';
else if(k==1)
c[a[i]]='B';
else if(k==2)
c[a[i]]='C';
else
c[a[i]]='D';
j=1;
}
p[k]=0;
}
}

for(l=0;l<n;++l)
if(m[a[i]][l]==1){

if(c[l]=='Z'){
for(j=0;j<n;++j)
if(m[l][j]==1){
if(c[j]!='Z'){
p[c[j]-'A']=1;
}
}

j=0;
for(k=0;k<4;k++){
if(p[k]==0&&j==0){
if(k==0)
c[l]='A';
else if(k==1)
c[l]='B';
else if(k==2)
c[l]='C';
else
c[l]='D';
j=1;
}
p[k]=0;
}
}
}
}

// Bicoloring ? //

l=0;
for(i=0;i<n;++i)
if(c[i]=='C' || c[i]=='D')
{ l=1; break; }

if(l==0)
printf("BICOLORABLE.\n");
else
printf("NOT BICOLORABLE.\n");

}

return 0;
}

``````

### Re: 10004 - Bicoloring WA

Posted: Fri Apr 08, 2011 12:26 pm
my problem gives me correct output for all possible input given in different threads, but it is WA. what is the problem can anyone tell me please...
here is the code

Code: Select all

``````#include<iostream>
#include<cstdio>
#include<queue>
#define MAX 201
using namespace std;

queue<int>que;
int n,m;
int path[MAX][MAX];
int color[MAX];

void initialize(){
int i,j;
for(i=0; i<MAX; i++){
for(j=0; j<MAX; j++){
path[i][j] = 0;
}
color[i] = 0;
}
}

int bfs(int u){
int temp;
int i;
que.push(u);
color[u] = 1;
while(!que.empty()){
temp = que.front();
que.pop();
for(i=0; i<n; i++){
if(path[temp][i]==1){
if(color[i]==0){
que.push(i);
if(color[temp] == 1)
color[i] = 2;
else color[i] = 1;
}
else if(color[i] == color[temp])
return 0;
}
}
}
return 1;
}

int main(){
int a,b,i,value;
//freopen("10004.txt","r",stdin);
while(scanf("%d",&n)==1&&n){
scanf("%d",&m);
initialize();
for(i=0; i<m; i++){
scanf("%d %d",&a,&b);
path[a][b] = path[b][a] = 1;
}
if(m>0)
value = bfs(a);
else
value = 1;

if(value==0)printf("NOT BICOLORABLE.\n");
else printf("BICOLORABLE.\n");
}
return 0;
}

``````

### Re: 10004 - Bicoloring - Runtime Error

Posted: Tue Jul 26, 2011 2:13 am
My solution is getting Runtime Error in 0.000s, but it works for all instances I've found in this board.
I don't know what is wrong. Is there a special test case that my code is not ready for?

Here is my code:

Code: Select all

``````#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <cstring>

using namespace std;

#define MAX_V   205
#define RED     0
#define BLACK	1
#define EMPTY  -1

vector<int> colors(MAX_V, EMPTY);
vector<int> grafo[MAX_V];	/* lista de adjacencias */

void reset()
{
for (int i = 0; i < MAX_V; i++)
{
colors[i] = EMPTY;
grafo[i].clear();
}
}

int coloring(int v, int cor)
{
int anticor = 1-cor;
colors[v] = anticor;

vector<int>::iterator it;
for (it = grafo[v].begin(); it != grafo[v].end(); it++)
{
if (colors[*it] == EMPTY)
{
if (coloring(grafo[v][*it], anticor) == 0)
return 0;
}
else if (colors[*it] == anticor) return 0;
}

return 1;
}

int main(int argc, char** argv)
{
int	n_vertices, n_arestas;  /* number of vertices and arestas */
int	x, y;
int   is_bicolor;

while (1)
{
cin >> n_vertices;
if (n_vertices == 0) break;

cin >> n_arestas;

reset();

while (n_arestas--)
{
cin >> x >> y;
grafo[x].push_back(y);
grafo[y].push_back(x);
}

/* verifica se eh bicolor */
colors[0] = BLACK;
for (int i = 0; i < grafo[0].size(); i++)
if (colors[i] == EMPTY)
is_bicolor = coloring(i, BLACK);

if (is_bicolor)
cout << "BICOLORABLE." << endl;
else
cout << "NOT BICOLORABLE." << endl;
}

return 0;
}
``````