View Code of Problem 104

#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<climits>
#include<cmath>
#include<unordered_map>
#include<set>

using namespace std;


int main()
{
	int n, v1, v2, t;

	while (cin >> n >> v1 >> v2 >> t) {

		n = n * 1000;

		if (v1 <= v2) {

			cout << "NO" << endl;
			continue;
		}
			
		double sub = v1 - v2;	//速度差
		double time = (double)(n / sub);	//sub不能为0

		if (time <= t)
			printf("%.2lf\n", time);
		else
			cout << "NO" << endl;

	}
}