为什么自己测试样例就是对的呢？

第五组样例：

23.234 12.123
-99.99 99.99
-1 -100

样例输出：

489.20

我的输出：

489.20

我的代码：

#include<cstdio>
#include<algorithm>
#include<cmath>
double A;
struct xy {
    double x;
    double y;
};
double dis(double x, double y, double x1, double y1, double x2, double y2) {
    return sqrt(pow(abs(x - x1), 2) + pow(abs(y - y1), 2)) + sqrt(pow(abs(x1 - x2), 2) + pow(abs(y1 - y2), 2)) + sqrt(pow(abs(x2 - x), 2) + pow(abs(y2 - y), 2));
}
int main() {
    xy a, b, c;
    scanf("%lf %lf\n%lf %lf\n%lf %lf", &a.x, &a.y, &b.x, &b.y, &c.x, &c.y);
    A = dis(a.x, a.y, b.x, b.y, c.x, c.y);
    if (floor(A) == A)printf("%d", int(A));
    else if (floor(A * 10) == A * 10)printf("%.1lf", A);
    else printf("%.2lf", A);
    return 0;
}