实现数组的全排列（百度笔试题）

#include <iostream>
using namespace std;

void Permutation(int* arr,int len,int length)
{
    if(!arr && length<1)
        return;
    if(len == length)
    {
        for(int i=0;i<length;++i)
            cout << arr[i];
        cout << endl;
    }
    else
    {
        for(int j =len;j<length;++j)
        {
            int tmp = arr[j];
            arr[j] = arr[len];
            arr[len] = tmp;

            Permutation(arr,len+1,length);

            tmp = arr[j];
            arr[j] = arr[len];
            arr[len] = tmp;
        }
    }
}


int main()
{
    int arr[] = {1,2,3};
    Permutation(arr,0,3);

    return 0;
}