二分查找

題目來源於leetcode

class Solution {
   public int search(int[] nums,int target){
        int n=nums.length;
        int i=0,j=n,m;
        while(i<j){
            m=i+(j-i)/2;
            if(nums[m]==target){
                return m;
            }else if(nums[m]<target){
                i=m+1;
            }else{
                j=m;
            }
        }
        return -1;
    }
}
    public static void main(String[] args){
        Solution s= new Solution();
        int[] nums=new int[]{-1,0,3,5,9,12};
        int target =9;
        int a= s.search(nums,target);
        System.out.println(a);
    }