Problem:
Score : 200 points

Problem Statement

Two children are playing tag on a number line. (In the game of tag, the child called "it" tries to catch the other child.) The child who is "it" is now at coordinate A, and he can travel the distance of V per second.
The other child is now at coordinate B, and she can travel the distance of W per second.

He can catch her when his coordinate is the same as hers.
Determine whether he can catch her within T seconds (including exactly T seconds later).
We assume that both children move optimally.

Constraints

-10^9 \leq A,B \leq 10^9

1 \leq V,W \leq 10^9

1 \leq T \leq 10^9

A \neq B

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A V
B W
T

Output

If "it" can catch the other child, print YES; otherwise, print NO.

Sample Input 1

1 2
3 1
3

Sample Output 1

YES

Sample Input 2

1 2
3 2
3

Sample Output 2

NO

Sample Input 3

1 2
3 3
3

Sample Output 3

NO

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)


import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		idea2();
	}

	// これで提出したら不正解だった…原因は不明
	private static void idea1() {

		// 入力
		Scanner sc = new Scanner(System.in);
		long a = sc.nextInt();
		long v = sc.nextInt();
		long b = sc.nextInt();
		long w = sc.nextInt();
		long t = sc.nextInt();

		// 子Bの逃げる速さが、鬼Aと同速かそれ以上だったら、永遠に追いつけない
		if (v <= w) {
			System.out.println("NO");
			return;
		}

		// ２人の距離は１秒にどれくらい縮まるか？
		long speed = v - w;

		// ２人は最初どのくらい離れているか？
		long dis = (a < b) ? (b - a) : (a - b);

		// 追いつくのに何秒かかるか？
		long need = dis / speed;

		// t秒以内に追いつけたらYES
		System.out.println((need <= t) ? "YES" : "NO");

	}

	private static void idea2() {

		// 入力
		Scanner sc = new Scanner(System.in);
		long a = sc.nextInt();
		long v = sc.nextInt();
		long b = sc.nextInt();
		long w = sc.nextInt();
		long t = sc.nextInt();

		// ２人は最初どのくらい離れているか？
		long dis = (a < b) ? (b - a) : (a - b);

		for (int i = 1; i <= t; i++) {
			// ふたりの距離を更新
			dis = dis - v + w;

			// 追いついたらYES
			if (dis <= 0) {
				System.out.println("YES");
				return;
			}

		}

		System.out.println("NO");

	}

}