N后问题

回溯法：

#include<iostream>

using namespace std;

int solve[100];
int count = 0, N;

void PrintSolve(){
	cout << count << ':';
	for(int i = 0; i < N; i++)
		cout << ' ' << solve[i];
	cout << endl;
}

void PutQueen(int step){
	for(int j = 0; j < N; j++){
		solve[step] = j;
		int flag = 1;
		for(int k = 0; k < step; k++){
			if(solve[k] == j || abs(step - k) == abs(solve[k] - j))
				flag = 0;
		}
		if(flag == 1){
			if(step == N - 1){
				PrintSolve();
				count++;
				return ;
			}else{
				PutQueen(step + 1);
			}
		}
	}
}



int main(){
	cout << "Please input the number of rows:" << endl;
	cin >> N;
	PutQueen(0);
	return 0;
}