问题：
Media = .85四舍五入 == .8
但是标准答案 == .9
——————————————————————————————————————————待解决————————————————————————————————————————————————————————————
/(ㄒoㄒ)//(ㄒoㄒ)//(ㄒoㄒ)/~~

#include <cstdio>

int main()
{
    double a, b, c, d;
    scanf("%lf%lf%lf%lf", &a, &b, &c, &d);

    double m;
    printf("Media: %.1lf\n", m = (a * 2 + b * 3 + c * 4 + d * 1) / 10);

    if(m >= 7) printf("Aluno aprovado.\n");
    else if(m < 5) printf("Aluno reprovado.\n");
    else
    {
        if(m >= 5 && m <= 7) printf("Aluno em exame.\n");
        double n, m2;
        scanf("%lf", &n);
        printf("Nota do exame: %.1lf\n", n);
        m2 = (m + n) / 2;
        if(m2 >= 5) printf("Aluno aprovado.\n");
        else printf("Aluno reprovado.\n");
        printf("Media final: %.1lf", m2);
    }

    return 0;
}