Leetcode 875 KoKo Eats banana

题意: 有个哥们吃香蕉，array为吃的大小，想在h时间吃完，但是又想用最少的时间吃完
https://leetcode.com/problems/koko-eating-bananas/

答案：二分答案，形如xxxooo，我要找到第一个o，但是由于我l+1了，所以r-l不加一

class Solution {
public:int minEatingSpeed(vector<int>& piles, int h) {int l = 1;int r = *max_element(piles.begin(), piles.end());while(l < r) {int mid = l + (r - l) / 2;if(eat(piles, mid) <= h) {r = mid;} else {l = mid + 1;}}return l;}int eat(vector<int>& piles, int s) {int ret = 0;for(int i = 0; i < piles.size(); i++) {ret += ceil((double)piles[i]/s);}return ret;}
};