class Solution {
public:
bool uniqueOccurrences(vector<int>& arr) {
unordered_map<int, int> occur;
for (const auto& x: arr) {
occur[x]++;
}
unordered_set<int> times;
for (const auto& x: occur) {
times.insert(x.second);
}
return times.size() == occur.size();
}
};
class Solution {
public:
bool uniqueOccurrences(vector<int>& arr) {
int count[2002] = {
0}; // 统计数字出现的频率
for (int i = 0; i < arr.size(); i++) {
count[arr[i] + 1000]++;
}
bool fre[1002] = {
false}; // 看相同频率是否重复出现
for (int i = 0; i <= 2000; i++) {
if (count[i]) {
// 非0
if (fre[count[i]] == false) fre[count[i]] = true;
else return false;
}
}
return true;
}
};
