1079 Just another Robbery 【概率揹包】
阿新 • • 發佈:2018-12-18
需要注意的是,要想連續搶多家銀行就得保證搶前面的銀行沒有被抓,所以樣例1中搶1和2兩家銀行的概率是 0.02 + (1-0.02)*0.03;
這裡的揹包dp[i] 中的i是val,價值;
#include <iostream> #include <cmath> #include <algorithm> #include <cstring> using namespace std; const int Maxn = 110; double dp[10005]; int val[105]; double p[105]; int main (void) { int T; cin >> T; for (int cas = 1; cas <= T; ++cas) { for (int i = 0; i < 10005; ++i) dp[i] = 1; int m; double limit; cin >> limit >> m; for (int i = 1; i <= m; ++i) { cin >> val[i] >> p[i]; } dp[0] = 0; for (int i = 1; i <= m; ++i) { for (int j = 10000-val[i]; j >= 0; --j) { if (dp[j] == 1) continue; dp[j+val[i]] = min (dp[j+val[i]], dp[j]+(1-dp[j])*p[i]); } } for (int i = 10000; i >= 0; --i) { if (dp[i] < limit || (fabs (limit-dp[i]) < 1e-6)) { cout << "Case " << cas << ": " << i << endl; break; } } } return 0; }