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

#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;
}