LeetCode第一題–兩個數的和

程式碼

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

public class AddTwoNumbers {

    public static int[] twoSum(int[] nums, int target) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();
        int length = nums.length;
        for (int
 
 i = 0 ; i < length ; i++){
            map.put(nums[i], i);   //存放值與位置的對應
        }

        for(int j = 0 ; j < length ; j++) {
            int key = target - nums[j];
            if (map.containsKey(key)) {
                int value = map.get(key);
                if(value != j){
                    return
 
 new int[]{j,value};
                }else{
                    continue;
                }

            }
        }
        return new int[]{-1,-1};   //否則說明不存在
    }

    public static void main(String[] args) {
        //int[] nums = {2,7,11,15};
        int[] nums = {3,2,4};
        /*int[] twoSum = twoSum(nums, 9);*/
 

        int[] twoSum = twoSum(nums, 6);
        for (int i : twoSum) {
            System.out.println(i + " ");
        }
    }

參考