1 #include<stdio.h> 2 #include<math.h> 3 int main(){ 4 5 float x1,y1,x2,y2; 6 7 scanf("%f %f %f %f",&x1,&y1,&x2,&y2); 8 printf("%f\n",sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2))); 9 10 return(0); 11 }