#include 
    
     #include 
     
      using namespace std;bool isLegal(int row,int col,vector
      
        &v,int n){	for(int i=0;i
       
        =0&&j>=0;--i,--j)		if(v[i][j]=='Q') return false;	for(int i=row-1,j=col+1;i>=0&&j
        
         > &res,vector
         
           &v,int row,int n){ if(row==n) { res.push_back(v); return; } for(int col=0;col
          
           > solveNQueens(int n){ vector
           
            
             > res; vector
             
               v(n,string(n,'.')); snqHelp(res,v,0,n); return res;}int main(int argc, char const *argv[]){ int n; cout<<"input n :"; cin>>n; vector
              
               
                > res=solveNQueens(n); for(auto vstr:res) { for(auto x:vstr) cout<
                
                 <