题解 | #二分查找-I#

//简单的二分查找
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
        if(nums.empty()){
            return -1;
        }
        int left=0,right=nums.size()-1;
        int mid;
        while(left<=right){
            mid = left + (right-left)/2;//用减法防止溢出
            if(target ==nums[mid]){
                return mid;
            }
            if(target<nums[mid]){
                right = mid-1;
                continue;
            }
            if(target>nums[mid]){
                left=mid+1;
            }
        }
        return -1;
    }
};