Java基础

2026

cat Main.java 
import java.util.*;

public class Main {
    public static int[] twoSum(int[] nums, int target) {

        HashMap<Integer, Integer> map = new HashMap<>();

        for (int i = 0; i < nums.length; i++) {

            int need = target - nums[i];

            if (map.containsKey(need)) {
                return new int[]{map.get(need), i};
            }

            map.put(nums[i], i);
        }

        return new int[]{};
    }

    public static void main(String[] args) {

        int[] nums = {2,7,11,15};

        int[] result = twoSum(nums, 9);

        System.out.println(Arrays.toString(result));
    }
}



➜  sh javac Main.java 
➜  sh java Main 
[0, 1]