LeetCode219——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.

实现：

class Solution {

public:

bool containsNearbyDuplicate(vector<int>& nums, int k) {

unordered_map<int, int> maps;

for (int i = 0; i < nums.size(); i++) {

auto search = maps.find(nums[i]);

if(search != maps.end()) {

if (i - search->second <=k){

return true;

} else {

search->second = i;

}

} else {

maps.insert(std::make_pair(nums[i], i));

}

}

return false;

}

};