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

        if (nums.size()==0){
            return -1;
        }

        else if (nums.size()==1){
            if (nums[0]==target){
                return 0;
            }else{
                return -1;
            }
        }else{

        int left = 0;
        int right = nums.size()-1;
        int mid;
        while(left<right){

            mid = (left + right) / 2;
            if(nums[mid]<target){

                left = mid+1;
                cout<<"< mid"<<mid<<"left"<<left<<"right"<<right<<endl;

            }else if(nums[mid]>=target){

                right = mid;
                cout<<"> mid"<<mid<<"left"<<left<<"right"<<right<<endl;

          

            }
            
            }
            mid = (left + right) / 2;
            if (nums[mid] == target){
                return mid;
            }

        }

        return -1;

    }
};