LeetCode:Contains Duplicate II

Problems:

Given an array of integers and an integer k, find out whether there there are two distinct indices i and j in the array such that nums[i] = nums[j] and the difference between i and j is at most k.

解法一：leetcode的测试用例不全

解法一：hashmap用来记录已出现的索引数

class Solution {
public:
bool containsNearbyDuplicate(vector<int>& nums, int k) {
if(nums.size()==0|| k==0) return false;

unordered_map<int,int> maping;

for(int i=0;i<nums.size();i++)
{
if(maping.find(nums[i])!=maping.end() && i-maping[nums[i]]<=k)
return true;
else
maping[nums[i]]=i;
}
return false;
}
};