统计字符串在字符串向量中出现的次数

#include <iostream>
#include <vector>
#include <unordered_map>

std::unordered_map<std::string, int> countOccurrences(const std::vector<std::string>& strings) {
    std::unordered_map<std::string, int> occurrences;

    for (const std::string& str : strings) {
        if (occurrences.find(str) != occurrences.end()) {
            occurrences[str]++;
        } else {
            occurrences[str] = 1;
        }
    }

    return occurrences;
}

int main() {
    std::vector<std::string> strings = {"apple", "banana", "apple", "orange", "banana", "apple"};
    std::unordered_map<std::string, int> occurrences = countOccurrences(strings);

    for (const auto& pair : occurrences) {
        std::cout << pair.first << ": " << pair.second << std::endl;
    }

    return 0;
}