1019 : New Tortoise and the Hare

时间限制Time Limit 1 秒Sec 内存限制Memory Limit 128 兆MB 提交次数Submitted 6 次Times 通过次数Solved 4 次Times

标准评测 Standard

从标准输入读入，结果写到标准输出。评测将输出拆成 token，与标准答案逐项比较，不按整段逐字节比对。 Read from standard input and write to standard output. The judge splits the output into tokens and compares them with the official answer; it does not compare raw bytes.

比对Compare	token 相同即通过。中间的空格、制表符、换行可多可少。Matching tokens pass. Extra spaces, tabs, or newlines between them are ignored.
不同则错Differs	token 个数或内容不同即错误。23 与 2 3、02 与 2、2.0 与 2 均视为不同。A different token count or value is wrong. 23 vs 2 3, 02 vs 2, and 2.0 vs 2 all differ.
输入Input	标准输入，格式见题面。Standard input; format as in the statement.
输出Output	标准输出。Standard output.

模板Template

C++ C Java Python

#include <iostream>
using namespace std;
int main() {
    int a, b;
    cin >> a >> b;
    cout << (a + b) << endl;
    return 0;
}

#include <stdio.h>
int main() {
    int a, b;
    scanf("%d%d", &a, &b);
    printf("%d\n", a + b);
    return 0;
}

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = in.nextInt();
        int b = in.nextInt();
        System.out.println(a + b);
    }
}

a, b = map(int, input().split())
print(a + b)

题目描述Description

The tortoise and the hare agreed to race again. The hare intends to let the tortoise run for a while, and then catch up with it before the finish line.

L，vt，vh，p respectively represent the length of the track, the speed of the tortoise (per second), the speed of the hare (per second), and the distance the tortoise has traveled when the hare starts.

Can the hare catch up with the tortoise?

输入格式Input

There are multiple test cases. Each line contains four integers L，vt，vh，p correspondingly.

10 <= L <= 1000, 1 <= vt < vh <= 1000, 1 <= p <= L.

The cases ends with EOF.

输出格式Output

Output a number a line corresponding to each case.

If the hare can catch up with the tortoise before (include) the finish line, the output is the time the hare need to catch up with the tortoise. The result should be accurated to two decimal places.

Otherwise, output -1.

样例Sample

提示Hint

EOF means the end of the file. In C language, we could use:

while(scanf("%d%d%d%d", &L, &vt, &vh, &p) != EOF)
{
    // Do what you need.
}

to recognise it.

出题Author

CSGrandeur

来源Source

HNCPC2024 Warmup