题目

704. 二分查找

题解

代码

public class code704 {
    public static 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) {
                left = mid + 1;
            } else if (nums[mid] > target) {
                right = mid - 1;
            }
        }
        return -1;
    }

    public static void main(String[] args) {
        int nums[] = { -1, 0, 3, 5, 9, 12 };
        int target1 = 9;
        int target2 = 2;
        int index1 = search(nums, target1);
        int index2 = search(nums, target2);
        System.out.println(index1);
        System.out.println(index2);
    }
}

参考

  1. 二分查找细节详解——题解一
  2. 画解算法：704. 二分查找——题解二