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[400100][10];
int sum[400100];
int pos=0;

bool insert1( char *word )
{
    int root=0;
    for(int i=0;i<strlen(word);i++)
    {   int ch=word[i]-'0';
        if(trie[root][ ch ]==0)
            trie[root][ ch ]=++pos;
        if(sum[root]==2&&root!=0)return false;
          sum[root]=1;
        root=trie[root][ch];


    }
      if(sum[root]!=1)  sum[root]=2;
      else  return false;
  return true;
}

int main()
{
    char word[10];int cas=0;
    while(gets(word))
    {   int ok=1;


        memset(sum,0,sizeof(sum));
        memset(trie,0,sizeof(trie));

          if(!insert1(word)){ok=0;}
        while(gets(word)&&word[0]!='9')
        {   if(ok==0)continue;
            if(!insert1(word)){ok=0;}


        }

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


    }
}

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