704.二分查找.java

/*
 * @lc app=leetcode.cn id=704 lang=java
 *
 * [704] 二分查找
 */

// @lc code=start
class Solution {
    public int search(int[] nums, int target) {
        int len = nums.length;
        if(nums == null || len == 0){
            return -1;
        }
        int i = 0;
        int j = len-1;
        while(i<=j){
            int mid = i+(j-i)/2;
            if(nums[mid] == target){
                return mid;
            }else if(nums[mid]<target){
                i = mid+1;
            }else if(nums[mid]>target){
                j= mid-1;
            }
        }

        return -1;

    }
}
// @lc code=end