n个元素中的r个元素的排列 [英] Permutation of r elements out of n

问题描述

我有以下用于置换的代码.但这会引发以下错误.

I have the following code for permutation. But it is throwing the below error.

11111
21111
31111
41111
51111
61111
71111
81111
91111
01111
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 10
    at Permutation.main(nPr_3.java:22)

代码是

HashSet<Integer[]> set = new HashSet<Integer[]>();
    int[] values = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
    int n = values.length;
    int r = 5; 
    int i[] = new int[r];
    int rc = 0;
    for(int j=0; j<Math.pow(n,r); j++)
    {
        Integer[] e = new Integer[r];
        while(rc<r)
        {
            e[rc] = values[i[rc]];
            System.out.print(values[i[rc]]);
            rc++;
        }
        System.out.println();
        rc = 0;
        set.add(e);
        while(rc<r)
        {
            if(i[rc]<n)
            {
                i[rc]++;
                break;
            }
            rc++;
        }
    }

谢谢.

推荐答案

引发异常时，i [rc](== i [0])已在i [rc] ++行中递增，直到值10 .但是值仅包含索引为0..9的元素.

When the exception is thrown i[ rc ]( ==i[ 0 ] ) has been incremented in the line i[rc]++ until the value 10. But values contains only elements with indecees 0..9.

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