数全排列问题

问题:给出一个数，计算出其全排列结果。

回答：方法一：

#include <iostream>
#include <cstdio>
#include <algorithm>
#define maxN 4
using namespace std;

int main()
{       
        int p[maxN] = {-1};
        for(int i=0; i<maxN; ++i)
        {       
                p[i] = i+1;
        }       
                
        do      
        {
                for(int i=0; i<maxN; ++i)
                {
                        printf("%d ",p[i]);
                }
                printf(" ");
        }while(next_permutation(p,p+maxN) );
        return 0;
}

方法二：

#include <stdio.h>
#include <stdlib.h>
//#define maxN 10
#define maxN 4

void permutation(int n,int arry[],int cur)
{
        if(cur == n)
        {
                int i=0;
                for(; i<n; ++i)
                {
                        printf("%d ",arry[i]);
                }
                printf(" ");
                return;
        }
        int iwhich=1;
        for(;iwhich<=n;++iwhich)
        {
                bool bInArry=false;
                int itmp=0;
                for(;itmp<cur;++itmp)
                {
                        if(iwhich == arry[itmp])
                        {
                                bInArry = true;
                                break;
                        }
                }//is in?
                if(false == bInArry)
                {
                        arry[cur] = iwhich;
                        permutation(n,arry,cur+1);
                }
        }
}

int main()
{
        int arry[maxN] = {-1};
        permutation(maxN,arry,0);
        return 0;
}