KMP算法（-）

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今天简单的给大家介绍一下KMP算法，

#include "stdafx.h"#include "string.h"int Index_Kmp(char S[],char T[],int next[],int pos,int n,int m){int i =pos-1;int j=-1;while( (i <n)&&(j <m)){if(j==-1||S[i]==T[j]){++i;++j;}else{j = next[j]-1;//J被回溯}for(int k=0;k<=i;k++){printf("%c ",S[k]);}printf("\n");for(int k=0;k<=i;k++){if(k<i-j)printf("  ");elseprintf("%c ",T[k+j-i]);}printf("\n");if(j>=m)return i- m;}return 0;}

//求next数组void makeNext(const char T[],int next[]){int i =0;int j =-1;next[0] = 0;while(i<strlen(T)){if(j==-1||T[i]==T[j]){++i;++j;next[i] = j+1;}else{j = next[j]-1;//J被回溯}}}int _tmain(int argc, _TCHAR* argv[]){int pos =0;int next[32]={0};char S[]={'a','b','a','b','a','a','c','a','b','a','a','b','a','b','a','a','b','a','b','c','a','\0'};//原串char T[]={'a','b','a','b','a','a','b','a','\0'};//目标串int n = strlen(S);int m = strlen(T);makeNext(T,next);pos =Index_Kmp(S,T,next,0,n,m);//返回原串在目标串中的起始位置printf("%d\n",pos);getchar();return 0;}

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