您的位置:首页 > 编程语言 > Java开发

leetcode 001 Tow Sum(java)

2015-12-08 21:42 507 查看


Two Sum

Given an array of integers, find two numbers such that they add up to a specific target number.
The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.
You may assume that each input would have exactly one solution.
Input: numbers={2, 7, 11, 15}, target=9

Output: index1=1, index2=2
 
提议:输入一个数组 和 一个目标数,数组中有两个数相加和为目标数,输出这两个数的下标且下标数小的先输出。
题解: 用了JAVA的hashmap。不是很会用。

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

public class Solution {
public static int[] twoSum(int[] nums, int target) {
int[] res =new int[2];

HashMap<Integer, Integer> map =new HashMap<Integer, Integer>();
for(int i=0;i<nums.length;i++){
if(!map.containsKey(target-nums[i])){
map.put(nums[i], i);
}
else{
res[0]=map.get(target-nums[i])+1;
res[1]=i+1;
break;
}
}
return res;
}

public static void main(String[] args) {
int[] nums=new int[]{1,5,5,10};
int[] res=new int[2];
res=twoSum(nums,10);
System.out.println(res[0]+" "+res[1]);
}

}
内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理 点击这里给我发消息
标签:  leetcode