10180 - Rope Crisis in Ropeland!

[Md. Abdulla Al Mamun Nayon]

Problem link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=1121
Getting Wrong Answer.
My conception:

My code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    int t;
    double x1, y1, x2, y2, r, d, d1, d2, t1, t2, pl, m, rl, theta, arc;
    scanf("%d", &t);
    while(t--){
        scanf("%lf %lf %lf %lf %lf", &x1, &y1, &x2, &y2, &r);
        if(x1 == x2) pl = fabs(x1);
        else if(y1 == y2) pl = fabs(y1);
        else{
            m = (y2 - y1) / (x2 - x1);
            pl = fabs((- m*x1 + y1) / sqrt(pow(m, 2) + 1));
        }
        if(pl > r)rl = sqrt(pow((x1-x2), 2) + pow((y1-y2), 2));
        else{
            t1 = sqrt(pow(x1, 2) + pow(y1, 2) - pow(r, 2));
            t2 = sqrt(pow(x2, 2) + pow(y2, 2) - pow(r, 2));
            d1 = sqrt(pow(x1, 2) + pow(y1, 2));
            d2 = sqrt(pow(x2, 2) + pow(y2, 2));
            d = sqrt(pow((x1-x2), 2) + pow((y1-y2), 2));
            theta = (acos((pow(d1, 2) + pow(d2, 2) - pow(d, 2)) / (2*d1*d2))) - ((acos((pow(d1, 2) + pow(r, 2) - pow(t1, 2)) / (2*d1*r))) + (acos((pow(d2, 2) + pow(r, 2) - pow(t2, 2)) / (2*r*d2))));
            arc = theta * r;
            rl = t1 + arc + t2;
        }
        printf("%.3lf\n", rl);
    }
    return 0;
}

Please, help.

[Md. Abdulla Al Mamun Nayon]

Some change in Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int ch(double a, double b)
{
    if((a > 0 && b < 0) || (a < 0 && b > 0))return 1;
    else return 2;

}

int main()
{
    int t;
    double x1, y1, x2, y2, r, d, d1, d2, t1, t2, pl, m, rl, theta, arc;
    scanf("%d", &t);
    while(t--){
        scanf("%lf %lf %lf %lf %lf", &x1, &y1, &x2, &y2, &r);

        if(x1 == x2){
            if(fabs(x1) <= r && fabs(y1) >= r && fabs(y2) >= r && ch(y1, y2) == 2)pl = fabs(y1);
            else pl = fabs(x1);
        }
        else if(y1 == y2){
            if(fabs(y1) <= r && fabs(x1) >= r && fabs(x2) >= r && ch(x1, x2) == 2)pl = fabs(x1);
            else pl = fabs(y1);

        }
        else{
            m = (y2 - y1) / (x2 - x1);
            pl = fabs((- m*x1 + y1) / sqrt(pow(m, 2) + 1));
        }

        if(pl >= r)rl = sqrt(pow((x1-x2), 2) + pow((y1-y2), 2));