题目:
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 absolute difference between i and j is at most k.
思路:
一开始读题不认真,我以为是重复元素的数组index之差等于k,但原来是at most k
,实际上问题比我想象的更简单了。用数据结构unordered_map来存储元素值以及数组下标。剩下的就很容易了。
代码实现:
class Solution {
public:
bool containsNearbyDuplicate(vector<int>& nums, int k) {
unordered_map<int, int> my_map;
for (int i = 0; i < nums.size(); ++i){
if (my_map.find(nums[i]) == my_map.end()){
my_map[nums[i]] = i;
}else{
if (i - my_map[nums[i]] <= k){
return true;
}else{
my_map[nums[i]] = i;
}
}
}
return false;
}
};