Question
Given an array of integers, find if the array contains any duplicates.
Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.
Example 1:
Input: [1,2,3,1] Output: true
Example 2:
Input: [1,2,3,4] Output: false
Example 3:
Input: [1,1,1,3,3,4,3,2,4,2] Output: true
Difficulty:Easy
Category:Array, Hash-Table
Analyze
Solution
class Solution {
public:
bool containsDuplicate(vector<int>& nums) {
std::unordered_map<int, int> counts;
for (int x : nums) {
std::unordered_map<int, int>::iterator got = counts.find(x);
if (got == counts.end())
counts.insert({x, 0});
else
return true;
}
return false;
}
};