题解 | 绕距

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

int main() {
    int x1, y1, x2, y2 = 0;
    double delta, dE, dM = 0;

    scanf("%d %d\n\r", &x1, &y1);

    scanf("%d %d\n\r", &x2, &y2);

    dE = sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2));

    dM = (abs(x1 - x2) + abs(y1 - y2));

    delta = fabs(dM - dE);

    printf("%.18lf\n\r", delta);

    return 0;
}