BNU Rugby Football

#include <stdio.h>#include <stdlib.h>#define ll long longll v[10050];int cmp(const void *a,const void *b){return *(ll *)b - *(ll *)a;}int main(){ll T,n,time,L,i,total;double ans;scanf("%lld",&T);while(T--){scanf("%lld%lld%lld",&n,&time,&L);total = L;for(i=1;i<=n;i++){scanf("%lld",&v[i]);total -= v[i]*time;}if(total > 0){printf("-1\n");continue;}qsort(&v[1],n,sizeof(v[1]),cmp);ll sum=0;for(i=1;i<=n;i++){if(sum + v[i]*time >= L){L -= sum;ans = time * (i-1) * 1.0;break;}sum += v[i]*time;}ans += L*1.0/v[i];printf("%.2lf\n",ans);}}

做道水题娱乐一下.hehe