#include #include #include #define MAX 110 using namespace std; int n; int sum; int ans[MAX]; int vis[3][MAX];///vis[0]代表列，vis[1]代表副对角线，vis[2]代表主对角线 void DFS(int x) { int i; if(xn+1) { sum++; if(sum<=3) { for(i=1; i<=n; i++) { if(i1) { printf("%d",ans[i]); } else { printf(" %d",ans[i]); } } printf("\n"); return ;
}
} for(i=1; i<=n; i++) { if(!vis[0][i]&&!vis[1][x+i]&&!vis[2][x-i+n]) { vis[0][i]=vis[1][x+i]=vis[2][x-i+n]=1; ans[x]=i; DFS(x+1); vis[0][i]=vis[1][x+i]=vis[2][x-i+n]=0;///状态恢复 } } } int main() { scanf("%d",&n); memset(ans,0,sizeof(ans)); memset(vis,0,sizeof(vis)); DFS(1); printf("%d\n",sum); }