POJ 1064 Cable master 【二分答案】

和杭电那一题一样，只不过G++交不能通过，C++能过

wa了好多好多好多次-----------------------------------------

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include <cmath>
 5 #include<stack>
 6 #include<vector>
 7 #include<map>
 8 #include<set>
 9 #include<queue>
10 #include<algorithm>
11 using namespace std;
12
13 typedef long long LL;
14 const int INF = (1<<30)-1;
15 const int mod=1000000007;
16 const int maxn=10005;
17 const int Exp=1e-6;
18
19 double a[maxn];
20 int n,k;
21
22 bool ok(double x){
23     int ans=0;
24     for(int i=0;i<n;i++){
25         ans+=(int) (a[i]/x );
26     }
27     return ans>=k;
28 }
29
30 int main(){
31     scanf("%d %d",&n,&k);
32     for(int i=0;i<n;i++) scanf("%lf",&a[i]);
33
34     double lb=0,ub= INF,mid;
35     for(int i=0;i < 100;i++){
36         mid=(lb + ub)/2;
37         if(ok(mid)) lb=mid;
38         else ub=mid;
39
40     //    printf("lb=%lf\n",lb);
41     //    printf("ub=%lf\n",ub);
42     //    printf("mid=%lf\n",mid);
43     }
44     printf("%.2lf\n",(floor)(mid*100)/100);
45
46     return 0;
47 }