View Code of Problem 104

#include<stdio.h>
int main(){
	int n,v1,v2;
	float t; 
	while(scanf("%d%d%d%f",&n,&v1,&v2,&t)!=EOF){
		n=n*1000;
		if(v2>=v1)         
			printf("NO\n");
		else {
			if(v1*t>v2*t+n){
				t=n*1.0/(v1-v2);
			printf("%.2f\n",t);
			}
			else printf("NO\n");
		}
	}
	return 0;
}