题目链接：?id=1064
题意：有n条绳子，他们的长度是Li，如果从他们中切割出K条长度相同的绳子，这相同的绳子每条有多长，输出至小数点后两位
“then the output file must contain the single number "0.00" (without quotes).”不是四舍五入到两位，一般四舍五入题目会说“bounded to”的提示
显然想得到的绳子越短就越能得到，绳子太长就得不到，二分搜即可
//236K94MS#include<cstdio>#include<algorithm>#include<iostream>#include<cmath>using namespace std;int n,k;double a[10100];bool judge(double x){int cnt=0;for(int i=1;i<=n;i++){cnt+=a[i]/x;}return cnt>=k? 1:0;}int main(){scanf("%d%d",&n,&k);for(int i=1;i<=n;i++) scanf("%lf",&a[i]);double lb=0,ub=100100;while(ub-lb>1e-5){double mid=(lb+ub)/2;if(judge(mid)){lb=mid;}else{ub=mid;}}printf("%.2f\n",floor(ub*100)/100);return 0;}
，旅游时最好的习惯：找个舒适的小店，挑张雅致的明信片，
