[c++]数组全排列

Posted 2022-11-29 adream307

#include <vector>
#include <functional>
#include <iostream>

using namespace std;

constexpr int empty_val = -1;

void Permutation_List(vector<int> &array, int pos, function<void(const vector<int> &x)> &foo) 
    if (pos == array.size()) 
        foo(array);
    
    std::vector<bool> used_list(array.size(), false);
    for (int i = 0; i < pos; i++) 
        int v = array[i];
        used_list[v] = true;
    
    std::vector<int> remain_list;
    remain_list.reserve(array.size());
    for (int i = 0; i < used_list.size(); i++) 
        if (used_list[i] == false) remain_list.push_back(i);
    
    for (auto x : remain_list) 
        array[pos] = x;
        Permutation_List(array, pos + 1, foo);
        array[pos] = empty_val;
    


int main() 
    vector<int> array(5, -1);
    function<void(const vector<int> &x)> foo = [](const vector<int> &x) 
        for (int v : x) 
            std::cout << v << " ";
        
        std::cout << std::endl;
    ;
    Permutation_List(array, 0, foo);

程序输出

0 1 2 3 4 
0 1 2 4 3 
0 1 3 2 4 
0 1 3 4 2 
0 1 4 2 3 
0 1 4 3 2 
0 2 1 3 4 
0 2 1 4 3 
0 2 3 1 4 
0 2 3 4 1 
0 2 4 1 3 
0 2 4 3 1 
0 3 1 2 4 
0 3 1 4 2 
0 3 2 1 4 
0 3 2 4 1 
0 3 4 1 2 
0 3 4 2 1 
0 4 1 2 3 
0 4 1 3 2 
0 4 2 1 3 
0 4 2 3 1 
0 4 3 1 2 
0 4 3 2 1 
1 0 2 3 4 
1 0 2 4 3 
1 0 3 2 4 
1 0 3 4 2 
1 0 4 2 3 
1 0 4 3 2 
1 2 0 3 4 
1 2 0 4 3 
1 2 3 0 4 
1 2 3 4 0 
1 2 4 0 3 
1 2 4 3 0 
1 3 0 2 4 
1 3 0 4 2 
1 3 2 0 4 
1 3 2 4 0 
1 3 4 0 2 
1 3 4 2 0 
1 4 0 2 3 
1 4 0 3 2 
1 4 2 0 3 
1 4 2 3 0 
1 4 3 0 2 
1 4 3 2 0 
2 0 1 3 4 
2 0 1 4 3 
2 0 3 1 4 
2 0 3 4 1 
2 0 4 1 3 
2 0 4 3 1 
2 1 0 3 4 
2 1 0 4 3 
2 1 3 0 4 
2 1 3 4 0 
2 1 4 0 3 
2 1 4 3 0 
2 3 0 1 4 
2 3 0 4 1 
2 3 1 0 4 
2 3 1 4 0 
2 3 4 0 1 
2 3 4 1 0 
2 4 0 1 3 
2 4 0 3 1 
2 4 1 0 3 
2 4 1 3 0 
2 4 3 0 1 
2 4 3 1 0 
3 0 1 2 4 
3 0 1 4 2 
3 0 2 1 4 
3 0 2 4 1 
3 0 4 1 2 
3 0 4 2 1 
3 1 0 2 4 
3 1 0 4 2 
3 1 2 0 4 
3 1 2 4 0 
3 1 4 0 2 
3 1 4 2 0 
3 2 0 1 4 
3 2 0 4 1 
3 2 1 0 4 
3 2 1 4 0 
3 2 4 0 1 
3 2 4 1 0 
3 4 0 1 2 
3 4 0 2 1 
3 4 1 0 2 
3 4 1 2 0 
3 4 2 0 1 
3 4 2 1 0 
4 0 1 2 3 
4 0 1 3 2 
4 0 2 1 3 
4 0 2 3 1 
4 0 3 1 2 
4 0 3 2 1 
4 1 0 2 3 
4 1 0 3 2 
4 1 2 0 3 
4 1 2 3 0 
4 1 3 0 2 
4 1 3 2 0 
4 2 0 1 3 
4 2 0 3 1 
4 2 1 0 3 
4 2 1 3 0 
4 2 3 0 1 
4 2 3 1 0 
4 3 0 1 2 
4 3 0 2 1 
4 3 1 0 2 
4 3 1 2 0 
4 3 2 0 1 
4 3 2 1 0