Immediate Decodability HDU1305

类似phonelist  一次ac

判断失败主要有两个要点

1. 是否包含了某段的结尾结点   说明某段被此段包含

2.此段的结尾结点是否为某段的痕迹   说明此段被包含

#include<bits/stdc++.h>
using namespace std;
int trie[][];
int sum[];
int pos=;

bool insert1( char *word )
{
    int root=;
    for(int i=;i<strlen(word);i++)
    {   int ch=word[i]-'';
        if(trie[root][ ch ]==)
            trie[root][ ch ]=++pos;
        if(sum[root]==&&root!=)return false;
          sum[root]=;
        root=trie[root][ch];

    }
      if(sum[root]!=)  sum[root]=;
      else  return false;
  return true;
}

int main()
{
    char word[];int cas=;
    while(gets(word))
    {   int ok=;

        memset(sum,,sizeof(sum));
        memset(trie,,sizeof(trie));

          if(!insert1(word)){ok=;}
        while(gets(word)&&word[]!='')
        {   if(ok==)continue;
            if(!insert1(word)){ok=;}

        }

       if(ok)printf("Set %d is immediately decodable\n",++cas);
        else printf("Set %d is not immediately decodable\n",++cas);

    }
}