HDU 2899 - Strange fuction (三分)
题目:https://vjudge.net/contest/312328#problem/A
题意:二分 找函数的最小值 (三分? 学到的 hhh )
mid and midmid
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include<bits/stdc++.h> using namespace std; int n,a; double f(double x) { return 6*pow(x,7)+8*pow(x,6)+7*pow(x,3)+5*pow(x,2)-a*x; } int main() { cin >> n; while(n--) { double l, r, mid, midmid; cin >> a; l = 0, r = 100; while(r - l > 1e-6) { mid = l+(r-l)/2; midmid = mid+(r-mid)/2; if(f(mid) > f(midmid)) l = mid; else r = midmid; } printf("%.4lf\n",f(mid)); } return 0; }