二分查找

在有序排列中查找目标值

// 二分查找，在循环体里面查找
class Solution {
    public int search(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1 ;
        while (left <= right) {// 表示在区间里只剩下一个元素的时候，我们还需要继续查找，
        	System.out.println(left + ";" + right);
			// int mid = (left + right)/2; // 避免整数溢出
			int mid = left + (right - left) / 2;
			if (nums[mid] == target) {
				return 1;
			} else if (nums[mid] < target){
				left = mid + 1;
			} else {
				right = mid - 1;
			}
			System.out.println(left + ";" + right);
		}
        return -1;
    }
}