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  1. #include <iostream>
  2. #include <vector>
  3. using namespace std;
  4. class Solution {
  5. public:
  6.     void solve(int i, int& n, vector<string>& tmp, vector<vector<string>>& ans, vector<bool>& c, vector<bool>& md, vector<bool>& td) {
  7.         if (i == n) {
  8.             ans.push_back(tmp);
  9.             return;
  10.         }
  11.         string str(n, '.');
  12.         for (int j = 0; j < n; j++) {
  13.             if ((c[j] == false && md[i - j + n] == false && td[i + j] == false)) {
  14.                 str[j] = 'Q';
  15.                 c[j] = true;
  16.                 md[i - j + n] = true;
  17.                 td[i + j] = true;
  18.                 tmp.push_back(str);
  19.                 solve(i + 1, n, tmp, ans, c, md, td);
  20.                 tmp.pop_back();
  21.                 str[j] = '.';
  22.                 c[j] = false;
  23.                 md[i - j + n] = false;
  24.                 td[i + j] = false;
  25.             }
  26.         }
  27.     }
  28.     int totalNQueens(int n) {
  29.         vector<vector<string>> ans;
  30.         vector<string> tmp;
  31.         vector<bool> c(n, false), md(2 * n + 3, false), td(2 * n + 3, false);
  32.         solve(0, n, tmp, ans, c, md, td);
  33.         return ans.size();
  34.     }
  35. };
  36.  
  37. int main() {
  38.     int n = 1;
  39.     Solution s;
  40.     int totalSolutions = s.totalNQueens(n);
  41.     cout << "Total number of solutions for " << n << " queens: " << totalSolutions << endl;
  42.     return 0;
  43. }
  44.  
Success #stdin #stdout 0s 5308KB
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Standard input is empty
stdout
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Total number of solutions for 1 queens: 1
https://ideone.com/g7Z02w
language:
C++14 (gcc 8.3)
created:
174 days ago
visibility:
public

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