CF1286C1 Madhouse (Easy version) 题解

const int N=100+13;
char s[N],t[N];
std::vector<int> a[N][N],b[N][N];
int lena[N],lenb[N];
bool vis[N];
inline bool check(std::vector<int> a,std::vector<int> b){
	for(int i=0;i<26;++i)
		if(a[i]!=b[i]) return 0;
	return 1;
}
int n;
int main(){
	scanf("%d",&n);
	print('?'),print(' '),print(1),print(' '),println(n);flush();fflush(stdout);
	if(n==1){scanf("%s",s+1);print('!'),print(' '),println(s[1]);flush(),fflush(stdout);return 0;}
	int tt=n*(n+1)/2;
	while(tt--){
		scanf("%s",s+1);int l=strlen(s+1);
		std::vector<int> bb;bb.resize(26);
		for(int i=1;i<=l;++i) bb[s[i]-'a']++;
		a[l][++lena[l]]=bb;
	}
	print('?'),print(' '),print(2),print(' '),println(n);flush(),fflush(stdout);
	tt=(n-1)*n/2;
	while(tt--){
		scanf("%s",s+1);int l=strlen(s+1);
		std::vector<int> bb;bb.resize(26);
		for(int i=1;i<=l;++i) bb[s[i]-'a']++;
		b[l][++lenb[l]]=bb;
	}
	std::vector<int> ans;ans.resize(26);
	for(int i=1;i<=n;++i){
		memset(vis,0,sizeof vis);
		for(int j=1;j<=lena[i];++j){
			bool ok=0;
			for(int k=1;k<=lenb[i];++k)
				if(!vis[k]&&check(a[i][j],b[i][k])){vis[k]=1,ok=1;break;}
			if(!ok){
				std::vector<int> now=a[i][j];int c=0;
				for(int k=0;k<26;++k)
					if(now[k]>ans[k]){c=k;break;}
				ans[c]++;
				t[i]=(char)(c+'a');
				break;
			}
		}
	}
	print('!'),print(' ');
	for(int i=1;i<=n;++i) print(t[i]);flush();fflush(stdout);
	return 0;
}