Description:
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.
Code:
1 bool containsNearbyDuplicate(vector<int>& nums, int k) { 2 unordered_map<int,int>m; 3 int n = nums.size(); 4 for (int i = 0; i < n; ++i) 5 { 6 if ( m.count(nums[i]) && i - m[nums[i]] <= k) 7 return true; 8 else 9 m[nums[i]] = i; 10 } 11 return false; 12 }
原文：http://www.cnblogs.com/happygirl-zjj/p/4604850.html