#include<iostream>
int main() {
    char* seasons[] = {
        "winter", "spring", "summer", "autumn"
    };
    int n;
    std::cin >> n;
    std::cout << seasons[n % 12 / 3];
    return 0;
}

参考答案：

#include<iostream>

using namespace std;

int main()
{
    int b;
    scanf("%d", &b);
    if (b >= 3 && b <= 5) cout << "spring";
    if (b > 5 && b <= 8) cout << "summer";
    if (b > 8 && b <= 11) cout << "autumn";
    if (b > 11 && b >= 12 || b >= 1 && b <= 2) cout << "winter";

    return 0;
}