LeetCode-＞二分查找打卡

二分查找

class Solution {
    public int search(int[] nums, int target) {
        if(nums.length==1){
            return nums[0]==target?0:-1;
        }
        int left = 0;
        int right = nums.length-1;
        while(left<=right){
            int middle = (left+right)/2;
            if(nums[middle]<target){
                left = middle+1;
            }else if(nums[middle]>target){
                right = middle-1;
            }else{
                return middle;
            }
        }
        return -1;
    }
}

猜数字大小

class Solution {
    public int search(int[] nums, int target) {
        if(nums.length==1){
            return nums[0]==target?0:-1;
        }
        int left = 0;
        int right = nums.length-1;
        while(left<=right){
            int middle = (left+right)/2;
            if(nums[middle]<target){
                left = middle+1;
            }else if(nums[middle]>target){
                right = middle-1;
            }else{
                return middle;
            }
        }
        return -1;
    }
}