ZOJ 1084 贪心 给顶点染色，相邻顶点不能染同样的颜色 算法有问题不能保证是最优解但能A

贴代码：

#include <cstdio>
#include <cstring>
#define MAXN 30
int n;
bool edge[MAXN][MAXN];
int color()
{
    int vet[MAXN];
    int c[MAXN];
    int i,j;
    memset(vet,0xff,sizeof(vet));
    for( i=0; i<n; ++i)
    {
        memset(c,0,sizeof(c));
        for( j=0; j<n; ++j)
        {
            if(edge[i][j] && vet[j] != -1)
                c[vet[j]] = 1;
        }
        for(j=0; j<n; ++j)
            if(!c[j]) break;
        vet[i] = j;
    }
    int max = -1;
    for(int i=0; i<n; ++i)
        if(vet[i] > max) max = vet[i];
    return max+1;
}
int main()
{
    freopen("in.cpp","r",stdin);
    while(~scanf("%d",&n))
    {
        if(n==0) break;
        memset(edge,0,sizeof(edge));
        char a[34];
        for(int i=0; i<n; ++i)
        {
            scanf("%s",a);
            int len=strlen(a);
            int u = a[0]-'A';
            for(int j=2; j<len; ++j)
            {
                int v = a[j]-'A';
                edge[u][v] = edge[v][u] = 1;
            }
        }
        int p = color();
        if(p == 1)
            printf("%d channel",p);
        else
            printf("%d channels",p);
        printf(" needed.\n");
    }
    return 0;
}