【LeetCode】219 - 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.

 1 class Solution {
 2 public:
 3     bool containsNearbyDuplicate(vector<int>& nums, int k) {
 4         map<int,int> m;
 5         for(int i=0;i<nums.size();i++){
 6             if(m.find(nums[i])==m.end())
 7                 m[nums[i]]=i;
 8             else{
 9                 if(i-m[nums[i]]<=k)
10                     return true;
11                 else
12                     m[nums[i]]=i;
13             }
14         }
15         return false;
16     }
17 };