View Code of Problem 104

#include<stdio.h>
#include<math.h>
int main()
{ 
  float n,v1,v2,t,s;
  while(scanf("%f%f%f%f",&n,&v1,&v2,&t)!=EOF){
  	if(v1>v2){
  		if(v1*t-v2*t>=1000*n){
  		   s=n*1000/(v1-v2); 
  		   printf("%.2f\n",s);
	    }
	    else
	    	printf("NO\n");
	  
  }
  else printf("NO\n");
 
}
 return 0;
}