hoj 13786 Equivalent Passwords

//题目看不懂 水题都不会做 感觉自己好傻逼
#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <queue>
#include <limits.h>
#include <string.h>
#include <vector>
#include <map>
#include <math.h>
#define LL unsigned long long
#define INF 2100000000
#define fi first
#define se second
#define lowbit(x) (x&(-x))
#define eps 5e-7
using namespace std;
const int maxn=(int)1e5 +30;
const int MOD=(int)1e9+10;
const double PI=acos(-1.0) ;
char s[10];
int a[10];
int l;
int getnum(){
    int res=0;
    int i=0;
    while(s[l]){
        res*=10;
        a[l]=s[l]-‘0‘;
        res+=a[l];
        l++;
    }
    return res;
}
int n,t;
bool vis[6][maxn];
void dfs(int pos,int num,int q){
    num*=10;
    if(l==pos+1){
        if(a[pos]+q<10) {
            vis[l][num+a[pos]+q]=true;//printf("%d\n",num+a[pos]+q);
        }
        if(a[pos]-q>=0) {
            vis[l][num+a[pos]-q]=true;//printf("%d\n",num+a[pos]-q);
        }
        return ;
    }
    if(a[pos]+q<10) dfs(pos+1,num+a[pos]+q,q);
    if(a[pos]-q>=0) dfs(pos+1,num+a[pos]-q,q);
}
int main(){
#ifdef shuaishuai
    freopen("C:\\Users\\hasee\\Desktop\\a.in","r",stdin);
    freopen("C:\\Users\\hasee\\Desktop\\b.txt","w",stdout);
#endif
    int t,kas=1;
    scanf("%d",&t);
    while(t--){
        scanf("%d\n",&n);
        int ans=0;
        memset(vis,false,sizeof vis);
        while(n--){
            scanf("%s",s);
            l=0;
            int num=getnum();
            if(!vis[l][num]) ans++;
            else continue;
            vis[l][num]=true;
           // for(int i=0;i<l;i++)printf("%d ",a[i]);printf("\n");
            for(int i=1;i<10;i++){
                dfs(0,0,i);
            }
        }
        printf("Case %d: %d\n",kas,ans);kas++;
    }

    return 0;
}