思路: (1)设立左右边界left、right (2)确定while循环的判断条件 (3)确定数组的中间元素,将查找的值与目标值比较

  • 若相等,查找成功返回此位置
  • 否则确定新的左右边界,继续该操作。

代码:

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