深度优先搜索 之 CODE[VS] 1294 全排列

/*
注意：
	输入输出采用scanf、printf，防止TLE。
 
两种实现方法：
	（1）void Solve(int numPos, int isUsed); // dfs
	（2）void SolveWithSTL();
	       C++ STL 自带函数，可生成全排列 next_permutation( )，
	       详细文档：http://www.cplusplus.com/reference/algorithm/next_permutation/?kw=next_permutation
*/

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstddef>
#include <iterator>
#include <algorithm>
#include <string>
#include <locale>
#include <cmath>
#include <vector>
#include <cstring>
#include <map>
#include <utility>
#include <queue>
#include <stack>
#include <set>
using namespace std;
const int INF = -0x3f3f3f3f;
const int MaxN = 55;
const int modPrime = 3046721;

int n;
int arr[15];

void Solve(int numPos, int isUsed)
{
    if (numPos == (n + 1))
    {
        for (int i = 1; i <= n; ++i)
        {
            printf("%d ", arr[i]);
        }
        printf("
");
    }
    for (int i = 1; i <= n; ++i)
    {
        if (!(isUsed&(1 << i)))
        {
            arr[numPos] = i;
            Solve(numPos + 1, isUsed|(1 << i));
        }
    }
}


void SolveWithSTL()
{
    for (int i = 1; i <= n; ++i)
    {
        arr[i] = i;
    }
    do
    {
        for (int i = 1; i <= n; ++i)
        {
            printf("%d ", arr[i]);
        }
        printf("
");
    } while (next_permutation(arr + 1, arr + n + 1));
}

int main()
{
#ifdef HOME
    freopen("in", "r", stdin);
    //freopen("out", "w", stdout);
#endif

    scanf("%d", &n);
    //Solve(1, 0);
    SolveWithSTL();

#ifdef HOME
    cerr << "Time elapsed: " << clock() / CLOCKS_PER_SEC << " ms" << endl;
    _CrtDumpMemoryLeaks();
#endif
    return 0;
}