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

double dist( double x1, double y1, double x2, double y2 );

int main()
{   
    double x1, y1, x2, y2;

    scanf("%lf %lf %lf %lf", &x1, &y1, &x2, &y2);
    printf("dist = %.2f\n", dist(x1, y1, x2, y2));

    return 0;
}

double dist( double x1, double y1, double x2, double y2 ){
    int c=0;
    double d=0;
    c=(double)pow((x1-x2),2)+ (double)pow((y1-y2),2);
    d=(double)pow(c,0.5);
    return  d;
}
能帮我看一下为什么d总是为1呢？？