1159 : Average of Two Numbers

时间限制Time Limit: 1 秒Sec
内存限制Memory Limit: 128 兆MB
提交次数Submitted: 2,015 次Times
通过次数Solved: 650 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.
时间与内存Time and memory	记这一份程序的 CPU 时间和内存峰值。题目上的时间限制、内存限制就是这一份的上限。The record is this program’s CPU time and peak memory. The limits on the problem apply to this one run.

模板Template

C++ C Java Python Kotlin

#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)

import java.util.Scanner
fun main() {
    val inp = Scanner(System.`in`)
    val a = inp.nextInt()
    val b = inp.nextInt()
    println(a + b)
}

题目描述Description

Given a list of n different numbers, which number in this list can be represented as an average of any two other numbers in the same list?

输入格式Input

There are multiple test cases.

The first line of each test case is an integer n, where 3 ≤ n ≤ 1000. The second line contains n different positive integers seperated by spaces, denoting the list of numbers. The numbers are in ascending order and every number in this list is less than 10⁹.

输出格式Output

For each test case, output the number of numbers in this list which can be represented as an average of any two other numbers in the same list.

样例Sample

提示Hint

In the first case, 2 can be represented by (1 + 3) / 2.

In the second case, 6 can be represented by (3 + 9) / 2, 7 can be represented by (6 + 8) / 2, 8 can be represented by (7 + 9) / 2.

出题Author

Staginner

来源Source

湖南省第十七届大学生计算机程序设计竞赛（HNCPC2021）

题目到此结束End of problem