【Leetcode】Two Sum

标签：leetcode   hashmap   map   

[Question]

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

public class Solution {
    public int[] twoSum(int[] numbers, int target) {
        int len=numbers.length;
        assert(len>=2);
        int[] result=new int[2];
        HashMap<Integer,Integer> map=new HashMap<Integer,Integer>();
        
        for(int i=0;i<len;i++){
            if(!map.containsKey(numbers[i])){
                map.put(target-numbers[i],i);
            }
            else{
                int index=map.get(numbers[i]);
                result[0]=index+1;
                result[1]=i+1;
                break;
            }
            
        }
        return result;
    }
}    

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【Leetcode】Two Sum

标签：leetcode   hashmap   map   

原文地址：http://blog.csdn.net/chongshijing/article/details/25023229