题解 | 绕距

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

int main() {
	int x1 = 0;
	int y1 = 0;
	int x2 = 0;
	int y2 = 0;
	scanf("%d %d", &x1, &y1);
	scanf("%d %d", &x2, &y2);
	double de = sqrt((pow((x1 - x2), 2)) + (pow((y1 - y2), 2)));
	int dm = abs(x1 - x2) + abs(y1 - y2);
	printf("%.18lf", fabs(de - dm));
	return 0;
}