Lightoj 1104 概率dp

/**********************jibancanyang************************** *Author*        :jibancanyang *Created Time*  : 四  5/12 23:37:26 2016 *File Name*     : .cpp**Problem**:**Analyse**:**Code**:***********************[e-mail]**********************/#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <set>#include <map>#include <string>#include <cmath>#include <cstdlib>#include <ctime>#include <stack>using namespace std;typedef pair<int, int> pii;typedef long long ll;typedef unsigned long long ull;vector<int> vi;#define pr(x) cout << #x << ": " << x << "  " #define pl(x) cout << #x << ": " << x << endl;#define pri(a) printf("%d\n",(a));#define xx first#define yy second#define sa(n) scanf("%d", &(n))#define sal(n) scanf("%lld", &(n))#define sai(n) scanf("%I64d", &(n))#define vep(c) for(decltype((c).begin() ) it = (c).begin(); it != (c).end(); it++) const int mod = int(1e9) + 7, INF = 0x3fffffff;const int maxn = 1e5 + 13;double dp[maxn];int main(void){#ifdef LOCAL    //freopen("/Users/zhaoyang/in.txt", "r", stdin);    //freopen("/Users/zhaoyang/out.txt", "w", stdout);#endif    ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);    int T; sa(T);    for (int cas = 1; cas <= T; cas++) {        dp[0] = 1;        int n; sa(n);        for (int i = 1; i <= n + 1; i++) {            dp[i] = dp[i - 1] * (n + 1.0 - i) / n;            //pr(i), pl(dp[i]);            if (dp[i] <= 0.5) {                printf("Case %d: %d\n", cas, i - 1);                break;            }        }    }    return 0;}