查询算法-二分查找算法

/**
 * 二分查找
 */

public class SkillBinarySearch {
    public static void main(String[] args) {
        int[] nums = {2, 9, 15, 33, 45, 54, 62, 74, 83, 91};
        BinarySearch tool = new BinarySearch();
        int index = tool.binarySearch(nums, 74);
        System.out.println(index);
    }
}

class BinarySearch {
    public int binarySearch(int[] nums, int target) {
        int start = 0;
        int end = nums.length - 1;

        while (start <= end) {
            int mid = start + (end - start) / 2;
            if (nums[mid] < target) {
                start = mid + 1;
            } else if (nums[mid] > target) {
                end = mid - 1;
            } else {
                return mid;
            }
        }
        return -1;
    }
}

代码运行结果：
7