C++统计vector元素出现次数方法

#include <iostream>
#include <vector>
#include <algorithm>  // std::count

int main() {
    std::vector<int> vec = {1, 2, 3, 2, 4, 2, 5};

    int target = 2;
    int count = std::count(vec.begin(), vec.end(), target);

    std::cout << "元素 " << target << " 出现了 " << count << " 次。\n";
    return 0;
}

std::vector<std::string> words = {"apple", "banana", "apple", "cherry", "apple"};
std::string key = "apple";
int n = std::count(words.begin(), words.end(), key);
std::cout << "单词 '" << key << "' 出现了 " << n << " 次。\n";