【實數二分/字首和維護】Best Cow Fences
阿新 • • 發佈:2018-11-03
Poj 2018 Best Cow Fences
實數二分+字首和維護
調了一晚上, 但發現沒什麼注意事項orz
無輸出只因eps定義成了int型QAQ哭唧唧
#include<cstdio> #include<iostream> using namespace std; const int sz = 100010; double eps = 1e-5; int n, f; double a[sz], b[sz], sum[sz]; bool check(double k) { double minn = 1e10, ans = -1e10;for(int i = 1; i <= n; i++) b[i] = a[i] - k; for(int i = 1; i <= n; i++) sum[i] = sum[i-1] + b[i]; for(int i = f; i <= n; i++) { minn = min(minn, sum[i - f]); ans = max(ans, sum[i] - minn); } if(ans >= 0) return true; else returnfalse; } int main() { scanf("%d%d", &n, &f); for(int i = 1; i <= n; i++) scanf("%lf", &a[i]); double l = -1e6, r = 1e6, ans = 0; while(r - l > eps) { double mid = (l + r) / 2.0; if(check(mid)) l = mid; else r = mid; } cout<< int(r * 1000) <<endl; return 0; }