---
tags: Cmoney_Java題目
---
Java_Cmoney_ft7206
===


1.需要的 function
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1.1 是否是等差數列
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public static boolean f(int[] arr) {
        int r = arr[1] - arr[0];
        for (int i = 0; i < arr.length - 1; i++) {
            if (r != arr[i + 1] - arr[i])
                return false;
        }
        return true;
    }

2.主程式
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1. 創造兩個陣列，一個是輸入的數列，一個是這個數列的"差"數列
2. 使用上面的 function，看 arr1 是不是等差數列

public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];
        int[] arr1 = new int[n - 1];
        for (int i = 0; i < n; i++)
            arr[i] = sc.nextInt();
        for (int i = 0; i < n - 1; i++)
            arr1[i] = arr[i + 1] - arr[i];
        boolean anw = f(arr1);
        System.out.println(anw);

    }

3.完整程式
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import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];
        int[] arr1 = new int[n - 1];
        for (int i = 0; i < n; i++)
            arr[i] = sc.nextInt();
        for (int i = 0; i < n - 1; i++)
            arr1[i] = arr[i + 1] - arr[i];
        boolean anw = f(arr1);
        System.out.println(anw);

    }

    public static boolean f(int[] arr) {
        int r = arr[1] - arr[0];
        for (int i = 0; i < arr.length - 1; i++) {
            if (r != arr[i + 1] - arr[i])
                return false;
        }
        return true;
    }
}