【Luogu1092】虫食算

//****************头文件****************#include<cstring>#include<cmath>#include<queue>#include<vector>#include<set>#include<string>#include<map>#include<iostream>#include<algorithm>#ifdef WIN32#define BIGN "%I64d"#else#define BIGN "%lld"#endifusing namespace std;typedef long long ll;int (int x,int y) {return x>y?x:y;}int mymin(int x,int y) {return x<y?x:y;}//****************全局常量****************const int INF=0x3f3f3f3f;//****************全局定义****************int n;int a[30];bool used[30];int jia1[30],jia2[30],he[30];//****************实现****************bool finaljudge(){	int jw=0;	for(int i=1;i<=n;i++)	{		int x=a[jia1[i]],y=a[jia2[i]],z=a[he[i]];		if( (x+y+jw)%n!=z ) return 0;		jw=(x+y+jw)/n;	}	return 1;}bool check(){	if(a[jia1[n]]+a[jia2[n]]>=n) return 0;	for(int i=1;i<=n;i++)//从后往前	{		int x=a[jia1[i]],y=a[jia2[i]],z=a[he[i]];		if(x<0 or y<0 or z<0) continue;//残缺		if( (x+y)%n!=z and (x+y+1)%n!=z ) return 0;	}	return 1;}int nxt[30];//新编号-Importantvoid Print(){	for(int i=1;i<=n;i++) printf("%d ",a[i]);	exit(0);}void dfs(int x){	if(x>n)	{		if(finaljudge()) Print();		return;	}		//for(int i=0;i<=n-1;i++) 玄学操作    for(int i=n-1;i>=0;i--)		if(used[i]==0)		{			a[ nxt[x] ]=i;			if(check())			{				used[i]=1;				dfs(x+1);				used[i]=0;			}			a[ nxt[x] ]=-1;		}}int cnt=0;//新编号-Importantvoid putnxt(int x){	if(used[x]==0)	{		used[x]=1;//借用		nxt[++cnt]=x;	}}//****************主函数****************char ch[30];int main(){	scanf("%d",&n);	scanf("%s",ch+1);for(int i=n;i>=1;i--) jia1[n-i+1]=ch[i]-'A'+1;	scanf("%s",ch+1);for(int i=n;i>=1;i--) jia2[n-i+1]=ch[i]-'A'+1;	scanf("%s",ch+1);for(int i=n;i>=1;i--) he[n-i+1]=ch[i]-'A'+1;		for(int i=1;i<=n;i++)//新编号-Important	{		putnxt(jia1[i]);		putnxt(jia2[i]);		putnxt(he[i]);	}		memset(used,0,sizeof(used));	memset(a,-1,sizeof(a));	dfs(1);}