8_ferzes

#include <iostream>
#include <cstdio>
#include <set>

using namespace std;

int cnt = 0;

class Queen{
public:
    int col, row;
    Queen* nb;
    bool canAttack(int Col, int Row);
    bool advance();
    Queen(int Col, Queen* Nb){
        col = Col;
        nb = Nb;
        row = 1;
    }
    ~Queen(){
        if(nb)
            delete nb;
    }
    bool findSolution();
    void print();
};

bool Queen::canAttack(int Col, int Row){
    if(Row == row)
        return true;
    if(abs(Row - row) == abs(Col - col))
        return true;
    if(nb)
        return nb->canAttack(Col, Row);
    return false;
}

bool Queen::advance(){
    if(row < 8){
        row++;
        return this->findSolution();
    }
    if(!nb)
        return false;
    if(nb->advance()){
        row = 1;
        return this->findSolution();
    }
    return false;
}

bool Queen::findSolution(){
    if(!nb)
        return true;
    while(nb->canAttack(col, row))
        if(!this->advance())
            return false;
    return true;
}

void Queen::print(){
    if(this->findSolution()){
        cnt++;
    }
}

int main(){
    Queen* lastQueen = NULL;
    set<Queen*> s;
    for(int i = 1; i < 9; i++){
        lastQueen = new Queen(i, lastQueen);
        lastQueen->findSolution();
    }
    while(lastQueen->findSolution()){
        lastQueen->print();
        lastQueen->advance();
    }
    cout << cnt << endl;
    delete lastQueen;
    system("pause");
    return 0;
}