hdu2454 Degree Sequence of Graph G(havel定理)

#include <cstdio>
#include <algorithm>
#define MAXN 1010
using namespace std;
int n;
int d[MAXN];
bool cmp(int a,int b){
return a>b;
}
int main(){
int T;
scanf("%d",&T);
while(T--){
scanf("%d",&n);
for(int i=0;i<n;++i)
scanf("%d",&d[i]);
sort(d,d+n,cmp);
if(d[0]>n-1){
printf("no\n");
continue;
}
bool f=false;
for(int i=0;i<n;++i){
sort(d,d+n,cmp);
if(d[0]==0)
break;
for(int j=1;j<=d[0];++j){
if(--d[j]<0){
f=true;
break;
}
}
d[0]=0;
if(f)
break;
}
if(!f)
printf("yes\n");
else
printf("no\n");
}
return 0;
}