技術標籤：Java

1. 陣列，第一題

import java.util.*;
public class Array1 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int[] num=new int[]{8,4,2,1,23,344,12,};
        int sum=0;

        for (int i = 0; i < num.length; i++) {
            sum= sum +
 
 num[i];
            System.out.print(num[i]+",");
        }
        System.out.println("數列的和："+sum);
        System.out.println("請輸入一個數：");
        int n = input.nextInt();
        boolean b=false;

        for (int i = 0; i <num.length ; i++) {
            if (n == num[
 
i]) {
                b = true;
            }
        }
        if(b){
            System.out.println("你猜對了，有這個數字！");
        }else{
            System.out.println("很遺憾猜錯了！");
        }
    }
}

2. 陣列，第二題

public class Array2 {
    public static void main(String[] args) {
        int
 
[]  price =new int[]{2800,2900,2750,3100};
        int min =price[0];

        for (int i = 0; i < price.length; i++) {
            if(min>price[i]){
                min=price[i];
            }
        }
        System.out.println("最低價為："+min);
    }
}

3. .編寫一個程式隨機產生10個0到50之間的整數並且這些整數不能重複出現。
Import java.util.Random;
Random r = new Random(); //建立一個生成隨機數的例項
int randomNum = r.nextInt(51); // 0~50

import java.util.Random;
public class Array3 {
    public static void main(String[] args) {
        Random r= new Random();
        int[] a=new int[10];
        int ranNum;
        for (int i = 0; i < a.length; i++) {
            ranNum=r.nextInt(51);
                a[i]=ranNum;
        }
        for (int i = 0; i <a.length ; i++) {
            System.out.print(a[i]+" ");
        }
    }
}

4. 編寫一個氣泡排序演算法對一組亂序的整數進行排序。

import java.util.*;

public class Array4 {
    public static void main(String[] args) {
        int[] num = new int[]{15,46,77,91,22,10,45,78,55};
        int temp;
        for (int i = 1; i < num.length; i++) {
            for (int j = 0; j <num.length-i; j++) {
                if(num[j]>num[j+1]){
                    temp = num[j+1];
                    num[j+1] = num[j];
                    num[j] = temp;
                }
            }
        }
        System.out.println("升序：");
        for (int i = 0; i <num.length ; i++) {
            System.out.print(num[i]+" ");
        }
        System.out.println();

        for (int i = 1; i < num.length; i++) {
            for (int j = 0; j <num.length-i; j++) {
                if(num[j]<num[j+1]){
                    temp = num[j+1];
                    num[j+1] = num[j];
                    num[j] = temp;
                }
            }
        }
        System.out.println("降序：");
        for (int i = 0; i <num.length ; i++) {
            System.out.print(num[i]+" ");
        }
    }
}

5. 第四題，分別使用 “氣泡排序演算法” 和“java.util.Arrays類”實現

import java.util.Arrays;
public class Array5 {
    public static void main(String[] args) {

        char[] c = new char[]{'a','c','u','b','e','p','f','z'};
        char temp;
        int i,j;
        for (i = 1; i < c.length; i++) {
            for ( j = 0; j <c.length-i ; j++) {
                if(c[j]<c[j+1]){
                    temp = c[j+1];
                    c[j+1] = c[j];
                    c[j] = temp;
                }
            }
        }
        System.out.println("氣泡排序：");
        for ( i = 0; i <c.length ; i++) {
            System.out.print(c[i]+" ");
        }
        char[] c1= new char[]{'a','c','u','b','e','p','f','z'};
        System.out.println();
        Arrays.sort(c1);
        System.out.println("Arrays排序：");
        for ( i = c1.length-1; i>=0 ; i--) {
            System.out.print(c1[i]+" ");
        }
    }
}

6. 第五題，二維陣列，
要求：使用二維陣列儲存下表的字串資料。
提示：

i. 第二維陣列（即列）需要動態建立，先分配好第二維陣列的空間。
ii. 再將口決表存入對應位中。

public class Array6 {
    public static void main(String[] args) {
        int[][] result = new int[9][];
        int i,j;
        for ( i = 0; i < result.length; i++) {
            result[i] = new int[1+i];
        }
        for (i = 0; i < result.length; i++) {
            for ( j = 0; j <i+1 ; j++) {
                result[i][j]=(j+1)*(i+1);
                System.out.print((i+1)+" * "+(j+1)+" = "+result[i][j]+" \t");
            }
            System.out.println();
        }
    }
}