C语言中的cout是什么？听取蛙声WA一片qaqaaaaaa

6，8，9，11，12，13，14过不了

#include <stdio.h>
#include <math.h>
int main() {
    int A=0;
    scanf("%d",&A);
    if (A == 1) {
       printf("I love Luogu!");
    } else if (A == 2) {
       printf("6 4");
    } else if (A == 3) {
        int d=14,e=4;
        printf("%d\n%d\n%d\n",d/e,d/e*4,d%e);
    } else if (A == 4) {
        double f=500,g=3,h;
        h=f/g;
        printf("%.6g",h);
    } else if (A == 5) {
        int k;
        k=480/32;
        printf("%d",k);
    } else if (A == 6) {
        int l;
        l=sqrt(6*6+9*9);
        printf("%d",l);
    } else if (A == 7) {
        int m,n;
        m=110;
        n=90;
        printf("%d\n%d\n0\n",m,n);
    } else if (A == 8) {
        double p,q,r,s=3.141593;
        p=2*s*5;
        q=5*5*s;
        r=5*5*5*s*4/3;
        printf("%lf\n%lf\n%lf\n",p,q,r);
    } else if (A == 9) {
        printf("26");
    } else if (A== 10) {
         printf("9");  
    } else if (A== 11) {
        double x;
        x=100/(8-5);
        printf("%lf",x);
    } else if (A == 12) {
        printf("13\n""r"); 
    } else if (A == 13) {
        double y,s=3.141593;
        y=4/3*s*(4*4*4+10*10*10);
        printf("%lf",y);
    } else if (A == 14) {
        int price=110,people=10;
        double sum;
        sum=price*people;
        while(sum<3500){
            price--;
            people++;
        }
        if(sum>=3500){
            sum=round(sum*10000);
            printf("%.4g",price*people);
        }
    }
    return 0;
}