问题一百三十七：计算坐标上两点之间的距离

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

float distance(int a, int b, int c, int d);

int main(int argc, char *argv[])
{
      int a;
      int b;
      int c;
      int d;

      printf("Please enter the first coordinate points x:");     //输入第一个点 
      scanf("%d %d", &a, &b);
      printf("Please enter the second coordinate points y:");    //输入第二个点
      scanf("%d %d", &c, &d);

      printf("The distance between two points is %f\n", distance(a, b, c, d));

      system("PAUSE");  
      return 0;
}

// Calculate distances

float distance(int a, int b, int c, int d)     //计算两点的距离 
{
      int   x;
      int   y;
      float distance;

      x=abs(a-c);
      y=abs(b-d);
      distance=sqrt(x*x+ y*y);     

      return distance;
}