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Subarray Sum Zero

Subarray Sum Zero

题目地址

题目描述

Given an integer array, find a subarray where the sum of numbers is zero. Your code should return the index of the first number and the index of the last number.

代码

Approach #1 HashMap, 查找两个sum

public class Solution {
public ArrayList<Integer> subarraySum (int[] nums) {
ArrayList<Integer> result = new ArrayList<Integer>();
Map<Integer, Integer> hashMap = new HashMap<Integer, Integer>();
int sum = 0;
for (int i = 0; i < nums.length; i++) {
sum += nums[i];
if (sum == 0) {
result.add(0);
result.add(i);
return result;
}
​
if (hashMap.containsKey(sum)) {
int index = hashMap.get(sum);
result.add(index);
result.add(i);
return result;
}
​
hashMap.put(sum, i);
}
​
return result;
}
}