Q10573: Geometry Paradox

// Run time: 0.000
#include <stdio.h>
#include <math.h>
#define PI 2*acos(0.0)

int check(char *s);

int main()
{
    int N;
    int num;
    int r1, r2;
    int t;
    char str[6];
    double area;

    scanf("%d\n", &N);

    while (N--)
    {
        gets(str);

        num = check(str);

        // argument number
        if (num == 2)
        {
            sscanf(str, "%d%d", &r1, &r2);
            area = 2*r1*r2*PI;
        }
        else
        {
            sscanf(str, "%d", &t);
            area = double(t*t)/8.0*PI;
        }

        printf("%.4lf\n", area);
    }

    return 0;
}

int check(char *s)
{
    int i;

    for ( i = 0; s[i] != '\0'; i++)
        if (s[i] == ' ')
            return 2;

    return 1;
}