【LeetCode】【HOT】1. 两数之和（哈希表）

【LeetCode】【HOT】1. 两数之和

package hot;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

public class Solution1 {
    public static void main(String[] args) {
        int[] nums = {2,7,11,15};
        int target = 9;
        Solution1 solution = new Solution1();
        System.out.println(Arrays.toString(solution.method(nums, target)));
    }

    private int[] method(int[] nums, int target){
        Map map = new HashMap<>();
        for(int i = 0; i < nums.length; i++){
            if(map.containsKey(target - nums[i])){
                return new int[] {map.get(target - nums[i]), i};
            }
            map.put(nums[i], i);
        }
        return new int[0];
    }
}

//时间复杂度为 O(n)
//空间复杂度为 O(n)