4、12、13点WA！ 看看我的代码

#include<algorithm>
#include<iostream>
#include<bits/stdc++.h>
using namespace std;

int main(void)
{
    int T;
    double p=3.141593;
    cin>>T;
    if (T == 1)
    {
        cout << "I love Luogu!";
    }
    else if (T == 2)
    {
        cout <<6<<" "<<4;
    }
    else if (T == 3)
    {
        cout<<3<<endl<<12<<endl<<2;
    }
    else if (T == 4)
    {
        printf("%.6f",500*1.0/(1.0*3));
    }
    else if (T == 5)
    {
        cout<<(260+220)/(12+20);
    }
    else if (T == 6)
    {
        cout<<sqrt(36+81);
    }
    else if (T == 7)
    {
        printf("%d\n%d\n%d",110,90,0);
    }
    else if (T == 8)
    {
        double ans1=5*2*p;
        double ans2=25*p;
        double ans3=125*4*p/3;
        cout<<ans1<<endl<<ans2<<endl<<ans3;
    }
    else if (T == 9)
    {
        cout<<(((1+1)*2+1)*2+1)*2;
    }
    else if (T == 10)
    {
        //典型的牛吃草问题
        cout<<9;
    }
    else if (T == 11)
    {
        cout<<100*1.0/(3*1.0);
    }
    else if (T == 12)
    {
        char i[26];
        int id;
        int k=0; 
        for(char j='A';j<='Z';j++,k++)
        {
            i[k]=j;
            if(j=='M')
            {
                id=k;
            }
        }
        cout<<id<<i[17];
    }
    else if (T == 13)
    {
        double a=164;
        double b=pow(a,1.0/3);
        int c=b;
        cout<<c;
    }
    else if (T == 14)
    {
        cout<<50;
    }
    return 0;
}

哪里错了，给我指一下