第七章第五题（打印不同的教）(Print distinct numbers) - 编程练习题答案

// 缺陷版本
import java.util.Arrays;
import java.util.Scanner;

public class Ans7_5_page236 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter ten numbers: ");
        int[] numberList = new int[10];
        // int[] distinctList = {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1};
        int[] distinctList = new int[10];
        Arrays.fill(distinctList,-1);

        for (int i = 0; i < 10; i++)
            numberList[i] = input.nextInt();

        for (int i = 0; i < 10; i++) {
            for (int j = 0; j < 10;j++) {
                if (i == numberList[j])
                    distinctList[i] = numberList[j];
            }
        }

        int count = 0;
        for (int i = 0; i < 10; i++) {
            if (distinctList[i] != -1)
                count++;
        }
        System.out.print("The number of distinct number is " + count+
                "\nThe distinct numbers are: ");

        for (int i = 0; i < 10; i++) {
            if (distinctList[i] != -1) {
                System.out.print(distinctList[i] + " ");
            }
        }
    }
}

// 完善版本
import java.util.Arrays;
import java.util.Scanner;

public class Ans7_5_page236 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter ten numbers: ");
        int[] numberList = new int[10];

        int maxInt = -99;
        for (int i = 0; i < 10; i++) {
            numberList[i] = input.nextInt();
            if (numberList[i] > maxInt)
                maxInt = numberList[i];
        }

        int[] distinctList = new int[maxInt];
        Arrays.fill(distinctList, -99);

        int disNum = 0;
        for (int i = 0; i < maxInt; i++) {
            for (int j = 0; j < 10; j++) {
                if (i == numberList[j])
                    distinctList[i] = numberList[j];
                else if (distinctList[i] != -99)
                    disNum = distinctList[i];
            }
        }

        int count = 0;
        for (int i = 0; i < maxInt; i++) {
            if (distinctList[i] != -99) {
                count++;
            }
        }
        System.out.print("The number of distinct number is " + disNum +
                "\nThe distinct numbers are: ");

        for (int i = 0; i < maxInt; i++) {
            if (distinctList[i] != -99) {
                System.out.print(distinctList[i] + " ");
            }
        }
        System.out.print(maxInt);
    }
}

//        Enter ten numbers: 1 2 3 2 1 6 3 4 5 2
//        The number of distinct number is 5
//        The distinct numbers are: 1 2 3 4 5 6

//        Enter ten numbers: 11 22 33 22 11 66 33 44 55 67
//        The number of distinct number is 66
//        The distinct numbers are: 11 22 33 44 55 66 67