题解 | 绕距

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

int main()
{
	int a, b;
	int c, d;
	double e, f;
    scanf ("%d %d %d %d",&a,&b,&c,&d);
	e = fabs(a - c) + fabs(b - d);
	f = sqrt((a - c) * (a - c) + (b - d) * (b -d));
	printf("%lf", e - f);
	return 0;
}