Container và thuật toán STL trong C++

#include <stdio.h>

int main(void) {
    int values[] = {3, 8, 2, 7, 6};
    int even[5];
    int count = 0;
    int sum = 0;
    for (int index = 0; index < 5; ++index) {
        if (values[index] % 2 == 0) {
            even[count++] = values[index];
        }
    }
    for (int index = 0; index < count; ++index) {
        sum += even[index];
    }
    printf("count=%d sum=%d\n", count, sum);
}

#include <algorithm>
#include <iostream>
#include <iterator>
#include <numeric>
#include <vector>

int main() {
    std::vector values{3, 8, 2, 7, 6};
    std::vector<int> even;
    std::copy_if(values.begin(), values.end(),
                 std::back_inserter(even),
                 [](int value) { return value % 2 == 0; });
    std::cout << "count=" << even.size()
              << " sum="
              << std::accumulate(even.begin(), even.end(), 0) << '\n';
}