Leetcode 275. H 指数 II（DAY 184）---- 二分查找学习期

• • 原题题目
  • 代码实现（首刷自解）

class Solution {
public:
    int hIndex(vector& citations) {
        int left = 0,right = citations.back();
        while(left < right)
        {
            int mid = (left + right + 1)/2;
            auto iter = lower_bound(citations.begin(),citations.end(),mid);
            int lower_nums = iter - citations.begin();
            int upper_nums = citations.size() - lower_nums;
            if(upper_nums >= mid)   left = mid;
            else right = mid - 1;
        }
        return left;
    }
};