SolveNQueen.cpp

#include<iostream>
using namespace std;
const int D=10;
bool isSafe(int board[10][10],int i, int j,int n){
	for(int row=0;row<i;row++){
		if(board[row][j]==1){
			return false;
		}
	}
	int x = i;
	int y = j;
	while(x>=0&&y>=0){
		if(board[x][y]==1){
			return false;
		}
		x--;
		y--;
	}
	x = i;
	y = j;
	while(x>=0 && y<n){
		if(board[x][y]==1){
			return false;
		}
		x--;
		y++;
	}
	return true;
}
bool solveNQueen(int board[][10], int i, int n){
	if(i==n){
		// print the board
		for(int i=0;i<n;i++){
			for(int j=0;j<n;j++){
				if(board[i][j]==1){
					cout<<" Q ";
				}
				else{
					cout<<" _ ";
				}
			}
			cout<<endl;
		}
		cout<<"--------------------------"<<endl;
		return false;
	}
	// Recursive Case
	for(int j=0;j<n;j++){
		if(isSafe(board, i, j, n)){
			board[i][j]=1;
			
			bool nextQueenRakhPaye = solveNQueen(board, i+1, n);
			if(nextQueenRakhPaye){
				return true;
			}
			board[i][j] = 0;
		}
	}
	return false;
}
int main(){
	
	int n;
	cin>>n;
	
	int board[10][10] = {0};
	
	solveNQueen(board, 0, n);
	
	return 0;
}