LeetCode 219:Contains Duplicate II

LeetCode 219:Contains Duplicate II

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

 //給出一個整數數組，判斷該數組內是否有兩個元素值是相同的，且他們的索引值相差不大於k，是則返回true，否則返回false
 class Solution {
 public:
	 bool containsNearbyDuplicate(vector& nums, int k) {
		 map buf;
		 int n = nums.size();
		 for (int i = 0; i < n; i++)
		 {
			 if (buf.find(nums[i]) != buf.end() && i - buf[nums[i]] <= k)
			 {
				 return true;
			 }
			 else
			 {
				 buf[nums[i]] = i;
			 }
		 }

		 return false;
	 }
 };