LeetCode——Contains Duplicate II

Question

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.

Solution

哈希表。

Code

class Solution {
public:
bool containsNearbyDuplicate(vector<int>& nums, int k) {
map<int, int> table;
for (int i = 0; i < nums.size(); i++) {
if (table.find(nums[i]) == table.end())
table[nums[i]] = i;
else {
int front = table[nums[i]];
table[nums[i]] = i;
if (i - front <= k)
return true;

}
}
return false;
}
};