[leetcode]Contains Duplicate II

Contains Duplicate II

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 iand j is at most k.
题意：给出一组整数，从中找出是否存在下标i,j之间使得nums[i]=nums[j]并且两个下标之间存在至多k个不同元素。

class Solution {
public:
bool containsNearbyDuplicate(vector<int>& nums, int k) {
map<int, vector<int> > mivi;

for(int i = 0; i < nums.size(); i++){
mivi[nums[i]].push_back(i);
if(mivi[nums[i]].size() > 1){
vector<int> v = mivi[nums[i]];
if(v[v.size() - 1] - v[v.size() - 2] <= k) return true;
}
}

return false;
}
};