View Code of Problem 104

#include "stdio.h"
void main()
{	
	int n,v1,v2,t;
	double k;
	for(;scanf("%d%d%d%d",&n,&v1,&v2,&t)!=EOF;)
	{
		if(v1==v2)
			printf("NO\n");
		else if((v1-v2)*t<n*1000)
			printf("NO\n");
		else
		{
			k=(n*1000)/(v1-v2)*1.00;

            printf("%.2lf\n",k);
		}
	}
}