字典樹演算法

 

#include "stdio.h"   #include "string.h"   #include "stdlib.h"   struct dictree   {       struct dictree *child[26];       int n;   };   //結點結構，有26個子節點struct dictree *root;   void insert (char *source)   {       int len,i,j;       struct dictree *current,*newnode;       len=strlen(source);       if(len==0) return;       current=root;       for(i=0;i<len;i++)       {           if(current->child[source[i]-'a']!=0)           {            current=current->child[source[i]-'a'];            current->n=current->n+1;         }        else           {               newnode=(struct dictree *)malloc(sizeof(struct dictree));               for(j=0;j<26;j++)                   newnode->child[j]=0;             current->child[source[i]-'a']=newnode;               current=newnode;            current->n=1;            }       }   }   int find(char *source)   {       int i,len;       struct dictree *current;      len=strlen(source);    if(len==0) return 0;       current=root;       for(i=0;i<len;i++)       {           if(current->child[source[i]-'a']!=0)               current=current->child[source[i]-'a'];           else return 0;       }       return current->n;   }   int main(){    char temp[11];    int i,j;    root=(struct dictree *)malloc(sizeof(struct dictree));       for(i=0;i<26;i++)           root->child[i]=0;       root->n=1000;     while(gets(temp),strcmp(temp,"")!=0)        insert(temp);    while(scanf("%s",temp)!=EOF)    {        i=find(temp);        printf("%d\n",i);    }}