This is my code.
#include<stdio.h>
#include<math.h>
double min(int t,int s)
{
    switch (t)
    {
        case 1:
            return 2*s;
        case 2:
            return (double)s;
        default:
            return ((s/2)*sqrt(3.0));
    }
}
double max(int t,int s)
{
    switch (t)
    {
        case 1:
            return 2*s;
        case 2:
            return (s*sqrt(2.0));
        default:
            return (double)s;
    }
}
void main()
{
    int htype,hsize;
    int type,size;
    double max_len,min_len;
    int n,c=0;
    int i;
    scanf("%d %d",&htype,&hsize);
    max_len=max(htype,hsize);
    scanf("%d",&n);
    for (i=0;i<n;i++)
    {
        scanf("%d %d",&type,&size);
        min_len=min(type,size);
        if (min_len<=max_len)
            c++;
    }
    printf("%d",c);
}

Please tell me whats wrong..

Perhaps, the error is in the function "min".
In case of triangle you

return ((s/2)*sqrt(3.0));

But in C++ when "s" is "int" and "2" is "int", you will get not float division but only integer division. So when s==3, for example,

((s/2)*sqrt(3.0))==1*sqrt(3.0)

You may write "s/2.0".

Thanks..AC now. Such a silly mistake.