fork download 
  1. #include <iostream>
  2. #include <vector>
  3. #include <string>
  4. #include <algorithm>
  5. using namespace std;
  6.  
  7. vector<string> result;
  8. vector<int> stack;
  9. vector<bool> visited;
  10.  
  11. void backtrack(int n, string current) {
  12.     if (current.size() == n) {
  13.         // 检查结果是否已存在，避免重复添加
  14.         if (find(result.begin(), result.end(), current) == result.end()) {
  15.             result.push_back(current);
  16.         }
  17.         return;
  18.     }
  19.  
  20.     if (!stack.empty()) {
  21.         int top = stack.back();
  22.         stack.pop_back();
  23.         backtrack(n, current + to_string(top));
  24.         stack.push_back(top);
  25.     }
  26.  
  27.     for (int i = 1; i <= n; ++i) {
  28.         if (!visited[i]) {
  29.             visited[i] = true;
  30.             stack.push_back(i);
  31.             backtrack(n, current);
  32.             stack.pop_back();
  33.             visited[i] = false;
  34.         }
  35.     }
  36. }
  37.  
  38. void clacExitMode(int n) {
  39.     visited.resize(n + 1, false);
  40.     backtrack(n, "");
  41.     sort(result.begin(), result.end());
  42.     for (const string& s : result) {
  43.         cout << s << " ";
  44.     }
  45.     cout << endl;
  46. }
  47.  
  48. int main() {
  49.     int n = 3;
  50.     clacExitMode(n);
  51.     return 0;
  52. }
Success #stdin #stdout 0s 5320KB
comments (?)
stdin 
Standard input is empty
stdout 
123 132 213 231 312 321
https://ideone.com/wQDKQP
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!