LightOJ 1027 概率
平均访问时间为sum(t)/n,期望次数为n/n1
#include <cstdio> #include <cstdlib> #include <cstring> #include <cmath> #include <cctype> #include <vector> #include <stack> #include <queue> #include <map> #include <algorithm> #include <iostream> #include <string> #include <set> #define X first #define Y second #define sqr(x) (x)*(x) #pragma comment(linker,"/STACK:102400000,102400000") using namespace std; const double PI = acos(-1.0); map<int, int>::iterator it; typedef long long LL ; template<typename T> void checkmin(T &x, T y) {x = min(x, y);} template<typename T> void checkmax(T &x, T y) {x = max(x, y);} int main() { int T, n; scanf("%d", &T); for(int t = 1; t <= T; ++t) { scanf("%d", &n); int n1 = 0, sum = 0; for(int i = 0; i < n; ++i) { int a; scanf("%d", &a); if(a > 0)++n1; sum += abs(a); } printf("Case %d: ", t); if(n1==0) { puts("inf"); } else { int g = __gcd(sum, n1); printf("%d/%d\n", sum/g, n1/g); } } return 0; }