kmp标准模板

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstdlib>
using namespace std;
void prefix_table(char pattern[],int prefix[],int n)  //前缀表
{
 prefix[0]=0;
 int len=0;  //被检索的i前面（即（i-1））的所有字符的最大公共前后缀的长度
 int i=1;
 while(i<n)
 {
  if(pattern[i]==pattern[len])
  {
   len++;
   prefix[i]=len;
   i++;
  }
  else
  {
   if(len>0)
    len=prefix[len-1];    //回溯
   else
   {
    prefix[i]=0;
    i++;
   }
  }
 }
}
void move_prefix_table(int prefix[],int n)
{
 for(int i=n-1;i>0;i--)
  prefix[i]=prefix[i-1];
 prefix[0]=-1;
}
void kmp_search(char text[],char pattern[])
{
 int n=strlen(pattern);
 int m=strlen(text);
 int* prefix=(int*)malloc(sizeof(int)*n);
 prefix_table(pattern,prefix,n);
 move_prefix_table(prefix,n);
 //text[i]      len(text)    =m
 //pattern[j]   len(pattern) =n
 int i=0;
 int j=0;
 while(i<m)
 {
  if(j==n-1 && text[i]==pattern[j])
  {
   printf("Found pattern at %d\n",i-j);
   j=prefix[j];
  }
  if(pattern[j]==text[i])
  {
   i++; j++;
  }
  else
  {
   j=prefix[j];
   if(j==-1)
   {i++; j++;
   }
  }
 }
}
int main()
{
 char pattern[]="ABABCABAA";
 char text []="ABABABCABAABABABAB";
 /*int prefix[9];;
 int n=9;
 prefix_table(pattern,prefix,n);
 move_prefix_table(prefix,n);
 for(int i=0;i<9;i++)
  printf("%d\n",prefix[i]);*/
 kmp_search(text,pattern);
 return 0;
}