题解 | 二分查找-I

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param nums int整型vector 
     * @param target int整型 
     * @return int整型
     */
    int search(vector<int>& nums, int target) {
        // write code here
        int left =0;
        int right = nums.size()-1;

        while (left<=right) {  //修改成<=
            int middle = (left+right)/2;
            if (nums[middle]==target) {
                return middle;
            }
            if (nums[middle]<target) {
                left = middle+1;
            }else{
                right =middle-1;
            }
        }
        return -1;//执行到while循环外没有返回说明没有找到
    }
};