W3School TIY Editor

#include <iostream> #include <vector> #include <algorithm> using namespace std; int main() { vector<int> numbers = {1, 2, 7, 5, 3, 5, 9, 2, 5}; int amount = count(numbers.begin(), numbers.end(), 5); cout << "数字 5 出现了 " << amount << " 次"; return 0; }