二分查找-I

基础二分写法

public int search (int[] nums, int target) {
        // write code here
        int l=nums.length;
        int i=0,j=l-1;
        while (i<=j){
            int mid=(i+j)/2;
            if(nums[mid]>target){
                j=mid-1;
            }else if(nums[mid]<target){
                i=mid+1;
            }else {
                return mid;
            }
        }

        return -1;

    }