ZOJ3827——Information Entropy

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3827

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/*<br>输出用f<br>*/<br>/************************************************ * Author        :Powatr * Created Time  :2015-8-18 10:37:09 * File Name     :ZOJ2827.cpp  ************************************************/   #include <cstdio> #include <algorithm> #include <iostream> #include <sstream> #include <cstring> #include <cmath> #include <string> #include <vector> #include <queue> #include <deque> #include <stack> #include <list> #include <map> #include <set> #include <bitset> #include <cstdlib> #include <ctime> using namespace std;   #define lson l, mid, rt << 1 #define rson mid + 1, r, rt << 1 | 1 typedef long long ll; const int MAXN = 100 + 10; const int INF = 0x3f3f3f3f; const int MOD = 1e9 + 7;   int main(){     int n; char s[10];     int a[MAXN];     int T;     scanf("%d", &T);     while(T--){     double ans = 0.0;         scanf("%d%s", &n, s);         for(int i = 1; i <= n; i++)             scanf("%d", &a[i]);         for(int i = 1; i <= n; i++){             if(a[i] == 0) continue;            double res = (double)(1.0*a[i]*(1.0*log(1.0*a[i]/100))/100);             if(s[0] == 'b')                 res = (double)res/(1.0*log(2.0));             if(s[0] == 'd')                 res = (double)res/(1.0*log(10.0));             ans += res;         }         printf("%.10f\n", -1.0*ans);     }     return 0; }