如何让代码更简洁

#include <bits/stdc++.h>
using namespace std;
const int N= 200+5;
int mp[N][N];
bool va[N],vb[N],vc[N];
int n, t=1,ans=0;
void dfs(int d){
	if(d==n+1){
		if(t<=3){
			for(int i=1;i<=n;i++)
				for(int j=1;j<=n;j++)
					if(mp[i][j]==1)cout<<j<<" ";
			cout<<endl; 
		}
		t++;
		ans++;
	}
	for(int i=1;i<=n;i++) {
		if(va[i]==0 and vb[d+i]==0 and vc[n+d-i]==0){
		va[i]=1;
		vb[d+i]=1;
		vc[n+d-i]=1;
		mp[d][i]=1;
		
		dfs(d+1);
		
		va[i]=0;
		vb[d+i]=0;
		vc[n+d-i]=0;
		mp[d][i]=0;
		}
	}
}
int main(){
	cin>>n;
	dfs(1);
	cout<<ans;
	return 0;
} 

求壶关