求求大佬救救孩子！！

如题，题主是个超级菜鸟的新手，已经改对了一道题了，实在是剩下的不知道错哪了。

救救！

下面是我的代码

（跪谢）

#include<stdio.h>
#include<math.h>
#include<iostream>
#define PI 3.141593
using namespace std;
int main ()
{
    char x;
    x=getchar();
    if(x=='1')
        printf("I love Luogu!");
    else if(x=='2')
        printf("6 4");
    else if(x=='3')
        printf("3\n12\n2\n");
    else if(x=='4'){
        float y;
        y=500/3.0;
        printf("%3.3f",y);
    }
    else if(x=='5'){
        int t;
        t=(260+220)/32;
        printf("%d",t);
    }
    else if(x=='6'){
        float l;
        l=sqrt(6*6+9*9);
        cout << l << endl;
        return 0;
    }
    else if(x=='7'){
        int one,two,three;
        one=100+10;
        two=one-20;
        three=two-two;
        printf("%d\n%d\n%d\n",one,two,three);
    }
    else if(x=='8'){
        int r=5;
        double C,S,V;
        C=2*PI*r;
        S=PI*r*r;
        V=4.0/3*PI*r*r*r;
        cout<<C<<"\n"<<endl;
        cout<<S<<"\n"<<endl;
        cout<<V<<"\n"<<endl;
            }
    else if(x=='9'){
        int e,f,g,h;
        h=1;
        g=(h+1)*2;
        f=(g+1)*2;
        e=(f+1)*2;
        printf("%d",e);
    }
    else if(x=='10'){
        int z,m,v;  
        z=(240-60)/24;
        m=240-30*z;
        v=(m+10*z)/10;
        printf("%d",v);
    }
    else if(x=='11'){
        int T;
        T=100/3;
        printf("%d",T);
    }
    else if(x=='12'){
        printf("13\nQ");

    }
    else if(x=='13'){
        double tiji;
        tiji=4.0/3*PI*4*4*4;
        double L=pow(tiji,1.0/3);
        printf("%.0ld",L);
    } 
    else{
        double price;
        price=(100-sqrt(100*100-4*2400))/2;
        printf("%.0lf",price);
    }
    return 0;
}