NC105-二分查找 题解

参考LeetCode 35. Search Insert Position

class Solution {
public:
    /**
     * 二分查找
     * @param n int整型 数组长度
     * @param v int整型 查找值
     * @param a int整型vector 有序数组
     * @return int整型
     */
    int upper_bound_(int n, int v, vector<int>& a) {
        // write code here
         int left = 0, right = n;
        while (left < right) {
            int mid = left + (right - left) / 2;
            if (a[mid] < v) left = mid + 1;
            else right = mid;
        }
        return right + 1;

        return n + 1;
    }
};