uva 10004 双着色

#include<stdio.h>#include<string.h>int flag;int map[210][210],n;int color[210];void dfs(int d,int c){if(flag)return;if(color[d]==0){color[d]=c;for(int i=0;i<n;i++){if(map[d][i]==1)dfs(i,-c);}}                            else{if(color[d]!=c)flag=1;}}int main(){int i,j,k,l,m;for(;;){scanf("%d",&n);if(n==0)break;scanf("%d",&m);memset(color,0,sizeof(color));memset(map,0,sizeof(map));for(i=0;i<m;i++){int a,b;          flag=0;scanf("%d %d",&a,&b);map[a][b]=1;map[b][a]=1;}dfs(0,1);if(!flag)printf("BICOLORABLE.\n");else printf("NOT BICOLORABLE.\n");}return 0;}