搞搞MATLAB
然后,看看论文,最后,今天的LeetCode犯琢磨,先抄下来先。
题目:
https://leetcode-cn.com/problems/top-k-frequent-elements/
class Solution {
public:
static bool cmp(pair<int, int>& m, pair<int, int>& n) {
return m.second > n.second;
}
vector<int> topKFrequent(vector<int>& nums, int k) {
unordered_map<int, int> occurrences;
for (auto& v : nums) {
occurrences[v]++;
}
// pair 的第一个元素代表数组的值,第二个元素代表了该值出现的次数
priority_queue<pair<int, int>, vector<pair<int, int>>, decltype(&cmp)> q(cmp);
for (auto& [num, count] : occurrences) {
if (q.size() == k) {
if (q.top().second < count) {
q.pop();
q.emplace(num, count);
}
} else {
q.emplace(num, count);
}
}
vector<int> ret;
while (!q.empty()) {
ret.emplace_back(q.top().first);
q.pop();
}
return ret;
}
};
作者:LeetCode-Solution
链接:https://leetcode-cn.com/problems/top-k-frequent-elements/solution/qian-k-ge-gao-pin-yuan-su-by-leetcode-solution/
来源:力扣(LeetCode)
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