文章目录
一、题目
1207. Unique Number of Occurrences
Given an array of integers arr, return true if the number of occurrences of each value in the array is unique or false otherwise.
Example 1:
Input: arr = [1,2,2,1,1,3]
Output: true
Explanation: The value 1 has 3 occurrences, 2 has 2 and 3 has 1. No two values have the same number of occurrences.
Example 2:
Input: arr = [1,2]
Output: false
Example 3:
Input: arr = [-3,0,1,-3,1,1,1,-3,10,0]
Output: true
Constraints:
1 <= arr.length <= 1000
-1000 <= arr[i] <= 1000
二、题解
cpp
class Solution {
public:
bool uniqueOccurrences(vector<int>& arr) {
unordered_map<int,int> map;
unordered_map<int,int> times;
unordered_map<int,int>::iterator it;
int n = arr.size();
for(int i = 0;i < n;i++){
map[arr[i]]++;
}
for (it = map.begin(); it != map.end();it++){
if(times[map[it->first]] == 0) times[map[it->first]]++;
else return false;
}
return true;
}
};