9-6每日一题：二分查找

Leetcode704. 二分查找

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int n = nums.size(), l = 0, r = n - 1;
        while (l < r) {
            int mid = l + r >> 1;
            if (nums[mid] >= target) r = mid;
            else l = mid + 1;
        }
        if (nums[l] == target) return l;
        else return -1;
    }
};