字符串匹配算法

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4、lt; 127; i+)tablei = l;for(int j = 0; j < l-1; j+)tablepatternj = l-1-j;void HorspoolMatch(string str, int table, string pSize)int main()string a = "abcdefg"string mode = "z"cout<<BruteForceStringMatch(a, mode)<<endl;return 0;#include<iostream>using namespace

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9、5;Ö´®·µ»Ø-1*/ShiftTable(pattern);int m=strlen(pattern);int n=strlen(text);int i=m-1;while(i <= n-1) int k=0; /Æ¥ÅäµÄ×Ö·û¸öÊý while(k<=m-1 && patternm-1-k = texti-k ) k+; if(k=m) ret

10、urn i-m+1; else i=i+table texti ; /ÒÔģʽ×îºóÒ»¸ö×Ö·ûÈ·¶¨Òƶ¯¾àÀë,ÓëB.MËã·¨µÄ×î´óÇ

11、48;±ð£¬¼ò»¯ÐÎʽreturn -1;int main()char p20,t1000;while(cin>>t && t!=".") int times=5; while(times-) cin>>p; cout<<HorspoolMatching(p,t)<<endl; return 1; #include <iostream> #include <algor

12、ithm> #include <string> #include <vector> #ifndef ssize_t typedef off_t ssize_t; #endif using namespace std; void compute_last_occurrence(const string& needle , vector<ssize_t>& last_occurrence) last_occurrence.resize(256,-1); for ( size_t i = 0 ; i < needle.size() ;

13、i+ ) last_occurrenceneedlei = i; void compute_prefix_function(const string& needle , vector<size_t>& prefix_function) if ( needle.size() = 0 ) return; prefix_function.resize( needle.size() , 0 ); size_t d = 0 ; for ( size_t i = 1 ; i < needle.size() ; i+ ) while ( d > 0 &&

14、; needled != needlei ) d = prefix_functiond-1; if ( needlei = needled ) d+; prefix_functioni=d; void compute_goodsuffix_heuristic( const string& needle ,vector<size_t>& goodsuffix_heristic) string reverse_needle; copy( needle.rbegin() , needle.rend() , back_inserter( reverse_needle ) )

15、; vector<size_t> prefix_function,reverse_prefix_function; compute_prefix_function( needle , prefix_function ); compute_prefix_function( reverse_needle , reverse_prefix_function ); size_t m = needle.size(); goodsuffix_heristic.resize( m + 1 , m - prefix_function m - 1 ); for ( size_t l = 1 ; l

16、<= m ; l+ ) size_t t = reverse_prefix_functionl-1; size_t j = m - t ; if ( goodsuffix_heristicj > l - t ) goodsuffix_heristicj = l - t ; void boyer_moore_matcher(const string& haystack,const string& needle) size_t n=haystack.size(); size_t m=needle.size(); if ( n = 0 | m = 0 | n < m

17、 ) cout<<"Invalid input"<<endl; return; vector<ssize_t> last_occurrence; compute_last_occurrence(needle,last_occurrence); vector<size_t> goodsuffix_heristic; compute_goodsuffix_heuristic( needle , goodsuffix_heristic ); size_t offset = 0 ; while ( offset <= n - m

18、 ) ssize_t j = m - 1 ; while ( j >= 0 && needlej = haystackoffset+j ) j-; if ( j < 0 ) cout<<"Find a match at offset "<<offset<<endl; offset += goodsuffix_heristic0; else offset += max<size_t>( goodsuffix_heristicj+1 , j - last_occurrencehaystackoffset

19、+j ); int main() string haystack,needle; while ( true ) cout<<"Input the haystack:"<<endl; getline(cin,haystack); cout<<"Input the needle:"<<endl; getline(cin,needle); cout<<"Match results:"<<endl; boyer_moore_matcher(haystack,needle)

20、; #include <iostream> #include <algorithm> #include <string> #include <iostream> using namespace std; int* GetNextVal(const char *s, int &len) len = strlen(s); int *next = new intlen; int i = 0; int j = -1; next0 = -1; while(i<len-1)/×¢ÒâÕâÀï¸úKMPº¯ÊýÀïÃæµÄ²»Í¬ if(j=-1 | si=sj) +i; +j; nexti = j; else j = nextj; return next; int KMP(const char *s, const char *t) int slen,tlen;