怎么会这样，求大佬调

xjx199 @ 2024-01-16 09:20:10

#include<bits/stdc++.h>
using namespace std;
int sum,n;
int a[1000001],b[1000001],c[100001],d[1000001];
void print()
{
    sum++;
    for(int i=1;i<=n;i++)
    {
        cout<<a[i];
        if(i==n) cout<<endl;
        else cout<<" ";
    }
}
int dfs(int k)
{
    for(int i=1;i<=n;i++)
    {
        if(b[i]==0 && d[k-i+15]==0 && c[k+i]==0)
        {
            a[k]=i;
            b[i]=1;
            c[i+k]=1;
            d[k-i+15]=1;
            if(i==n)
            {
                print();
            }
            else dfs(k+1);
            b[i]=0;
            c[k+i]=0;
            d[k-i+15]=0;
        }
    }
}
int main()
{
    int n;
    cin>>n;
    dfs(1);
    cout<<sum<<endl;
    return 0;
}

by wanghu @ 2024-02-02 10:58:16

@xjx199

#include<bits/stdc++.h>
using namespace std;
int sum,n;
int a[1001][1001],b[1000001],c[100001],d[1000001];//我习惯用二维数组，好输出
void print(){
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(a[i][j]==1){
                cout<<j<<" ";
            }
        }
        //cout<<endl;
    }
    cout<<endl;
}
void dfs(int k){    
    if(k>n){
        sum++;//不能边输出边计数，因为只输出前3个答案
        if(sum<=3){
            print();
        }
        return;
    }
    for(int i=1;i<=n;i++){
        if(b[i]==0 && d[k-i+n]==0 && c[k+i]==0){
            a[k][i]=1;
            b[i]=1;
            c[i+k]=1;
            d[k-i+n]=1;
            dfs(k+1);
            b[i]=0;
            c[k+i]=0;
            d[k-i+n]=0;
            a[k][i]=0;
         //你没有给a数组归0
        }
    }
    return;
}
int main()
{
    cin>>n;
    dfs(1);
    cout<<sum<<endl;
    return 0;
}