BF algorithm and KMP algorithm in string pattern matching

The editor of the blog Park is too hard to use ...

BF algorithm is the brute force algorithm, very simple, casually lifted a chestnut:

#include <iostream>#include<cstring>using namespacestd;//s[]: to match the chain//t[]: pattern stringintBfsearch (intStartCharS[],Chart[]) {    intSlen =strlen (S); intTlen =strlen (T); intI, J;  for(i =0; i < Slen-tlen; i++) {         for(j =0; J < Tlen; J + +)            if(S[i + j]! = T[j]) Break; if(J = =tlen) cout<< i +1<<Endl; }}intMain () {Chars[]="CABABAABCACB"; Chart[]="ABCAC"; Bfsearch (0, S, T); return 0;} 

KMP algorithm:

The main implementation content includes a GetNext function and a function to compare strings and patterns;

The implementation of GetNext function is the most important. Principles are described in a number of other articles. Here's where I feel more important.

intnext[ -];Chars[]="CABABAABCACB";Chart[]="ABCAC"; voidGetNext (Chart[]) {    intk=-1; intj=0; NEXT[J]=K;  while(t[j]!=' /'){        if(k==-1|| t[j]==T[k]) {k++; J++; NEXT[J]=K; }        Elsek=NEXT[K]; }}

One of the most important and most essential places in k=next[k];

S[] is a pattern string
NEXT[K] Stores the number of digits with the same k position prefix as the suffix,
Executed when t[j]!=T[k] appears
K = Next[k] Indicates the prefix of the bit (K-bit) before the current position is assigned to K, and
Suffix the same number of digits for the purpose of the next array of next[k] (i.e. p[next[k]])

Full code:

#include <iostream>#include<string.h>using namespacestd;intnext[ -];Chars[]="CABABAABCACB";Chart[]="ABCAC"; voidGetNext (Chart[]) {    intk=-1; intj=0; NEXT[J]=K;  while(t[j]!=' /'){        if(k==-1|| t[j]==T[k]) {k++; J++; NEXT[J]=K; }        Elsek=Next[k]; }}intKmpsearch (CharS[],intStartChart[]) {    intSlen =strlen (S); intTlen =strlen (T); intI=start; intj=0;  while(I<slen && j<Tlen) {                                            if(j==-1|| s[i]==T[j]) {i++; J++; }        ElseJ=Next[j]; }    if(t[j]==' /')        return(i-j+1); Else        return 0;}intMain () {getNext (T);  for(intk=0; t[k]!=' /'; k++) cout<<next[k]<<" "; cout<<Endl; cout<<kmpsearch (S),0, T); return 0;}

BF algorithm and KMP algorithm in string pattern matching