KMP代码实现

void GeneratePrefix(const string& pattern, int* prefix){int length = pattern.size();prefix[1] = 0;int LOLP = 0;           //LOLP表示最长的前缀数组int NOCM;              //number of characters matchedfor(NOCM = 2; NOCM <= length; ++NOCM){while(LOLP > 0 && pattern[NOCM-1] != pattern[LOLP])LOLP = prefix[LOLP];if(pattern[NOCM-1] == pattern[LOLP])++LOLP;prefix[NOCM] = LOLP;}}void KMPMatch(const string& pattern, const string& target){int size1 = pattern.size();int size2 = target.size();if(size1 > size2)return;int prefix[size1];GeneratePrefix(pattern, prefix);int NOCM = 0;for(int i = 0; i < size2; ++i){while(NOCM > 0 && pattern[NOCM] != target[i])NOCM = prefix[NOCM];if(pattern[NOCM] == target[i])++NOCM;if(NOCM == size1){cout << "Matched! The start index is:" << i-size1+1 << endl;NOCM = prefix[NOCM];}}}