生成排列数（java&c++)

[size=large]用递归的方法生成一列数的所有排列组合

public class Main {

	public static void main(String[] args) {
		Integer[] a = {1, 2, 3, 4};
		perm(a, 0, 3);
	}



	public static void perm(Object[] list, int k, int m) {
		if(k==m) {
			for(int i=0; i<=m; i++)
				System.out.print(list[i]);
			System.out.println();
		}

		else
			for(int i=k; i<=m; i++) {
				swap(list, k, i);
				perm(list, k+1, m);
				swap(list, k, i);
			}
	}

	public static void swap(Object[] list, int k, int m) {
		Object temp;
		temp = list[k];
		list[k] = list[m];
		list[m] = temp;
	}
}

void swap(int* list , int k, int m) {
    int temp;
    temp = list[k];
    list[k] = list[m];
    list[m] = temp;
}

void perm(int list[], int k, int m) {
    if(k==m) {
        for(int i=0; i<=m; i++) {
            cout<<list[i];
        }
        cout<<endl;
    }
    else {
        for(int i=k; i<=m; i++) {
            swap(list, k, i);
            perm(list , k+1, m);
            swap(list, k, i);
        }
    }
}

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