题解 | #二分查找-I#

import java.util.*;


public class Solution {
    /**
     * 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整型一维数组
     * @param target int整型
     * @return int整型
     */
    public int search (int[] nums, int target) {
        // write code here
        if (nums.length == 0) {
            return -1;
        }
        int leftIndex = 0;
        int rightIndex = nums.length - 1;
        do {
            int middleIndex = (leftIndex + rightIndex) / 2;
            if (nums[middleIndex] == target) {
                return middleIndex;
            }
            if (nums[middleIndex] > target) {
                rightIndex = middleIndex;
            }
            if (nums[middleIndex] < target) {
                leftIndex = middleIndex;
            }
        } while (rightIndex - leftIndex > 1);
        if (nums[leftIndex] == target) {
            return leftIndex;
        }
        if (nums[rightIndex] == target) {
            return rightIndex;
        }
        return -1;
    }
}