如何使用Java排序来输出排序的数字？

Question

这是我的Bubble Sort代码。我无法获得输出的实际排序值。该程序读取输入的数字，但不打印排序。 我不知道我必须做些什么来使他们排序。 任何建议或意见将有所帮助。

package sortingalgorithm2; 
import java.util.Scanner; 

public class Main { 

/** 
* @param args the command line arguments 
*/ 
public static void main(String[] args) 
{ 
    Scanner read = new Scanner (System.in); 
    int[] num = new int[15]; 
    int size = 15; 

    System.out.println("Enter 15 numbers: "); 
    for (int i=0; i <= size-1; i++) 
    { 
     num[i] = read.nextInt(); 

    } 

    for (int i=0; i <= size-1; i++) 
    { 
     if (num[i] >=1 && num[i] <= 1000) 
     { 
     System.out.println("The numbers you entered are: "); 
     System.out.println(+num[0]); 
     System.out.println(+num[1]); 
     System.out.println(+num[2]); 
     System.out.println(+num[3]); 
     System.out.println(+num[4]); 
     System.out.println(+num[5]); 
     System.out.println(+num[6]); 
     System.out.println(+num[7]); 
     System.out.println(+num[8]); 
     System.out.println(+num[9]); 
     System.out.println(+num[10]); 
     System.out.println(+num[11]); 
     System.out.println(+num[12]); 
     System.out.println(+num[13]); 
     System.out.println(+num[14]); 
    } 
    else 
    { 
     System.out.println("Data input is invalid. Enter a number between " 
       + 
       "1 and 1000."); 
     break; 
    } 
    } 

    BubbleSort (num); 
    for (int i=0; i < num.length; i++) 
    { 
     System.out.println("The sorted numbers are: "); 
     System.out.print(num[i]+ " "); 
    } 

} 

private static void BubbleSort(int[] num) 
{ 
    for (int i=0; i <= num.length; i++) 
     for (int x=1; x <= num.length; x++) 
      if (num[x] > num[x+1]) 
      { 
       int temp = num[x]; 
       num[x] = num[x+1]; 
       num[x+1] = temp; 
      } 

} 

} 

Answer 1

试试这个冒泡排序：

private static void BubbleSort(int[] num) { 
for (int i = 0; i < num.length; i++) { 
    for (int x = 1; x < num.length - i; x++) { 
     if (num[x - 1] > num[x]) { 
      int temp = num[x - 1]; 
      num[x - 1] = num[x]; 
      num[x] = temp; 

     } 
    } 
    } 
} 

Answer 2

要打印的实际数字在用户输入的顺序。试试这个：

int[] sortedNumbers = new int[15]; 

sortedNumbers = BubbleSort (num); 

    for (int i=0; i < sortedNumbers.length; i++) 
    { 
     System.out.println("The sorted numbers are: "); 
     System.out.print(sortedNumbers[i]+ " "); 
    } 



public static int[] BubbleSort(int [] num) 
{ 
    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]; 
       num [j] = num [j+1]; 
       num [j+1] = temp; 
      } 
     } 
    } 

    return num; 
} 

Answer 3

你传递数组变量num（这是不是静态）到冒泡（）（不返回一个值和阴影与自己全球num变量），并尝试使用同样的num变量来访问你的主要方法，这是不正确的排序数组。 真正的解决方法是在main方法之前（在类声明中）将变量num声明为静态。所以我已经在程序中进行了修改，这里是解决方案。

import java.util.Scanner; 

public class sol { 

static int num [] =new int [15]; //declaring num as static in the class definition. 
public static void main(String[] args) 
{ 
    Scanner read = new Scanner (System.in); 
    int size = 15; 

    System.out.println("Enter 15 numbers: "); 
    for (int i=0; i <= size-1; i++) 
    { 
     num[i] = read.nextInt(); 

    } 
    read.close(); 
    /*for (int i=0; i <= size-1; i++) 
{ 


    if (num[i] >=1 && num[i] <= 1000) 
    { 
    System.out.println("The numbers you entered are: "); 
    System.out.println(+num[0]); 
    System.out.println(+num[1]); 
    System.out.println(+num[2]); 
    System.out.println(+num[3]); 
    System.out.println(+num[4]); 
    System.out.println(+num[5]); 
    System.out.println(+num[6]); 
    System.out.println(+num[7]); 
    System.out.println(+num[8]); 
    System.out.println(+num[9]); 
    System.out.println(+num[10]); 
    System.out.println(+num[11]); 
    System.out.println(+num[12]); 
    System.out.println(+num[13]); 
    System.out.println(+num[14]); 
} 
else 
{ 
    System.out.println("Data input is invalid. Enter a number between " 
      + 
      "1 and 1000."); 
    break; 
} 
}*/ //I have disabled this just to check with the sort method. 

    BubbleSort();//no need to pass the array as it is static and declared as a  //class variable hence can be used to by all the methods of that class 
    System.out.println("The sorted numbers are: "); 
    for (int i=0; i < num.length; i++) 
    { 

     System.out.print(num[i]+ " "); 
    } 

} 

private static void BubbleSort() 
{ 
    for (int i=0; i < num.length; i++)// required changes in the looping 
     for (int x=0; x < num.length-i-1; x++) 
      if (num[x] > num[x+1]) 
      { 
       int temp = num[x]; 
       num[x] = num[x+1]; 
       num[x+1] = temp; 
      } 

} 

}

Answer 4

试试这个：

for (int i = 0; i < num.length; i++) { 
     for (int j = i + 1; j < num.length; j++) { 
      if (num[i] > num[j]) { 
       num[i] = num[i] + num[j] - (num[j] = num[i]); 
      } 
     } 
    }