【leetcode】N-Queens II

N-Queens II

Follow up for N-Queens problem.

Now, instead outputting board configurations, return the total number of distinct solutions.

 

 class Solution {
 public:
     int totalNQueens(int n) {
         vector<int> q(n,-);
         int result=;
         getQueens(,n,result,q);
         return result;
     }

     void getQueens(int level,int &n,int &result,vector<int> &q)
     {
         if(level==n)
         {
             result++;
             return;
         }
         bool flag=false;
         for(int i=;i<n;i++)
         {
             q[level]=i;
             if(isValid(q,level))
             {
                 getQueens(level+,n,result,q);
             }
             q[level]=-;
         }
     }

     bool isValid(vector<int> &q,int &level)
     {

         for(int i=;i<level;i++)
         {
             if(q[i]==q[level]||abs(q[level]-q[i])==abs(level-i)) return false;
         }

         return true;
     }

 };