【算法】二分查找

public class Solution {
    public int search(int[] nums, int target) {
    	int high = nums.length - 1;
        int low = 0;
        int mid = 0;

        if (target < nums[low] || target > nums[high] || low > high) {
            return -1;
        }

        while (low <= high) {
            mid = (low + high) / 2;
            // 比mid大则在左边，比mid小则在右边
            if (nums[mid] > target) {
                high = mid - 1;
            } else if (nums[mid] < target) {
                low = mid + 1;
            } else {
                return mid;
            }
        }
        return -1;
    }
}