思路

每组仅2至8个二进制串，9结束一组，按组号输出完整文本；小范围无需强制Trie，区别Phone List的T/n协议。

参考程序（C++11）

#include <bits/stdc++.h>
using namespace std;
int main(){string s;vector<string>a;int t=0;while(cin>>s){if(s!="9"){a.push_back(s);continue;}sort(a.begin(),a.end());bool ok=true;for(int i=1;i<(int)a.size();i++)if(a[i].compare(0,a[i-1].size(),a[i-1])==0)ok=false;cout<<"Set "<<++t<<" is "<<(ok?"":"not ")<<"immediately decodable\n";a.clear();}}