void BMY(string &pstr, const size_t &plen, string &sstr, const size_t &slen, int (&m1)[ALPHABET_SIZE], int (&m2)[ZuHe_SIZE], vector<int> &res)
{int i,j;  //i:模式串游标   j:文本串游标 i = j = plen-1; int cnt = -1;while(j < slen){num_bmy++;//模式串和文本串从后向前匹配 while( (i!=0) && pstr[i] == sstr[j]){--i;--j;bidui_bmy++;}bidui_bmy++;//发现一个匹配的模式串 if(i==0 && pstr[i] == sstr[j]){res.push_back(j);match_bmy++;}    //匹配成功及出现失配的情况 j += (plen-i-1);if(m1[sstr[j+1]] == 0 && m1[sstr[j+2]] == 0)            //尾1和尾2都不在模式串中j += (plen + 2);else if(sstr[j+1] == pstr[plen-1])                      //尾1在模式串尾j += 1;else if( (cnt = m2[sstr[j+1]*256+sstr[j+2]]) != -1)     //尾1和尾2的组合在模式串中 j += (plen - cnt); else if(sstr[j+2] == pstr[0])                           //尾2在模式串头 j += (plen + 1);elsej += (plen + 2);cnt = -1;i = plen - 1;}
}

#include <iostream>
#include <cstring>
#include <sstream>
#include <vector>
#include <algorithm>
#include <unordered_map>
#include <map>
#include <ctime>
#include <iterator>
#include <fstream>
using namespace std;#define ALPHABET_SIZE 32767
#define ZuHe_SIZE 32767int match_kmp = 0;
int match_bmy = 0;
int match_bm = 0;
int match_bmhs = 0;int num_kmp = 0;
int num_bmy = 0;
int num_bm = 0;
int num_bmhs = 0;int bidui_kmp = 0;
int bidui_bm = 0;
int bidui_bmy = 0;
int bidui_bmhs = 0;void InitBMHS(int *alphabet, string &des, size_t plen)
{for (int i=0; i<ALPHABET_SIZE; i++)alphabet[i] = plen;for (int i=0; i<plen; i++)alphabet[des[i]] = plen - i - 1;
}void sunday(string &src, size_t len_s, string &des, size_t len_d, int *alphabet, vector<int> &res)
{int i, pos = 0;for (pos = 1; pos <= len_s - len_d + 1;){num_bmhs++;for (i=pos+len_d-2; i>=pos-1 ; i--){if (src[i] == des[i-pos+1]){ bidui_bmhs++;} else if (src[i] != des[i-pos+1]){bidui_bmhs++;break;}}if ((i-pos+2+len_d) == len_d){match_bmhs++;res.push_back(pos-1);pos += len_d;}else{pos += alphabet[src[pos+len_d-1]] + 1;}}
}void initP(string &pstr, int (&m1)[ALPHABET_SIZE], int (&m2)[ZuHe_SIZE])
{int len = pstr.size();for(int i=0; i<len; ++i){m1[pstr[i]] = 1;}for(int i=0; i<len-1; ++i){m2[pstr[i]*256+pstr[i+1]] = i;}
}void BMY(string &pstr, const size_t &plen, string &sstr, const size_t &slen, int (&m1)[ALPHABET_SIZE], int (&m2)[ZuHe_SIZE], vector<int> &res)
{int i,j;  //i:模式串游标   j:文本串游标 i = j = plen-1; int cnt = -1;while(j < slen){num_bmy++;//模式串和文本串从后向前匹配 while( (i!=0) && pstr[i] == sstr[j]){--i;--j;bidui_bmy++;}bidui_bmy++;//发现一个匹配的模式串 if(i==0 && pstr[i] == sstr[j]){res.push_back(j);match_bmy++;}    //匹配成功及出现失配的情况 j += (plen-i-1);if(m1[sstr[j+1]] == 0 && m1[sstr[j+2]] == 0)          //尾1和尾2都不在模式串中j += (plen + 2);else if(sstr[j+1] == pstr[plen-1])                    //尾1在模式串尾j += 1;else if( (cnt = m2[sstr[j+1]*256+sstr[j+2]]) != -1)   //尾1和尾2的组合在模式串中 j += (plen - cnt); else if(sstr[j+2] == pstr[0])                         //尾2在模式串头 j += (plen + 1);elsej += (plen + 2);cnt = -1;i = plen - 1;}
}void GetNext(string p, int (&next)[ALPHABET_SIZE])
{  int pLen = p.size();  next[0] = -1;  int k = -1;  int j = 0;  while (j < pLen-1 )  {  if(k == -1 || p[j] == p[k]) //p[k]表示前缀，p[j]表示后缀
         {  ++k;  ++j;  next[j] = k;  // k == next[j-1] + 1
         }  else   {  k = next[k];  // next[k] == next[next[j]](递归的思想）
         }  }
}  void KMP_Search(string &s, size_t slen, string &p, size_t plen, int (&next)[ALPHABET_SIZE], vector<int> &res)
{  int i = 0;  int j = 0;  while (j < slen)  // i:模式串游标  j:文本串游标
    {  num_kmp++;//模式串和文本串从前向后匹配      while(i == -1 || s[j] == p[i])  {  i++;  j++;bidui_kmp++;if(i == plen) break; }bidui_kmp++;//找到匹配的模式串  if(i == plen){res.push_back(j-i);j += 1;i = 0;         match_kmp++;}//出现失配的情况 else  {  //如果i != -1，且当前字符匹配失败（即S[i] != P[j]），则令j不变，i = next[j],使模式串右移    i = next[i];  }  }
} void BuildBadC(string &pattern, size_t pattern_length, unsigned int *badc, size_t alphabet_size)
{  unsigned int i;  for(i = 0; i < alphabet_size; ++i)  {  badc[i] = pattern_length;  }  for(i = 0; i < pattern_length; ++i)  {  badc[pattern[i] ] = pattern_length - 1 - i;  }
}  void BuildGoodS(const char *pattern, size_t pattern_length, unsigned int* goods)
{  unsigned int i, j, c;  for(i = 0; i < pattern_length - 1; ++i)  {  goods[i] = pattern_length;  }  //初始化pattern最末元素的好后缀值  goods[pattern_length - 1] = 1;  //此循环找出pattern中各元素的pre值，这里goods数组先当作pre数组使用  for(i = pattern_length -1, c = 0; i != 0; --i)  {  for(j = 0; j < i; ++j)  {  if(memcmp(pattern + i, pattern + j, (pattern_length - i) * sizeof(char)) == 0)  {  if(j == 0)  {  c = pattern_length - i;  }  else  {  if(pattern[i - 1] != pattern[j - 1])  {  goods[i - 1] = j - 1;  }  }  }  }  }  //根据pattern中个元素的pre值，计算goods值  for(i = 0; i < pattern_length - 1; ++i)  {  if(goods[i] != pattern_length)  {  goods[i] = pattern_length - 1 - goods[i];  }  else  {  goods[i] = pattern_length - 1 - i + goods[i];  if(c != 0 && pattern_length - 1 - i >= c)  {  goods[i] -= c;  }  }  }
}  void BM(string &pattern, size_t pattern_length, string &text, size_t text_length, unsigned int *badc, unsigned int *goods, vector<int> &res)
{  unsigned int i, j;  i = j = pattern_length - 1;  while(j < text_length)  {  num_bm++;//发现目标传与模式传从后向前第1个不匹配的位置  while((i != 0) && (pattern[i] == text[j]))  {  --i;  --j;  bidui_bm++;}  bidui_bm++;//找到一个匹配的情况  if(i == 0 && pattern[i] == text[j])  {  res.push_back(j);  j += goods[0];  match_bm++;}  else  {  //坏字符表用字典构建比较合适  j += goods[i] > badc[text[j]] ? goods[i] : badc[text[j]];  }  i = pattern_length - 1;  }
}  int main()
{string pstr = "want";ifstream fin("2.txt");string sstr( (istreambuf_iterator<char>(fin)), istreambuf_iterator<char>() );for(int i=0; i<5; i++)sstr.insert(sstr.end(),sstr.begin(),sstr.end());const char* pstr_ = pstr.data();const size_t plen = pstr.size();const size_t slen = sstr.size();/*BMHS*/int alphabet[ALPHABET_SIZE] = { 0 };InitBMHS(alphabet, pstr, plen);vector<int> res4;clock_t start4 = clock();sunday(sstr, slen, pstr, plen, alphabet, res4); cout<<"BMHS 时间: "<<(double)(clock()-start4)/CLOCKS_PER_SEC*1000<<"ms"<<endl;cout<<"BMHS 识别模式串个数: "<<match_bmhs<<endl;cout<<"BMHS 匹配次数: "<<num_bmhs<<endl;cout<<"BMHS 比对次数："<<bidui_bmhs<<endl<<endl;
//    for(auto it : res4)
//        cout<<it<<endl;/*KMP*/int next[ALPHABET_SIZE];for(int i=0; i<ALPHABET_SIZE; i++)next[i] = -1;GetNext(pstr, next);vector<int> res2;clock_t start2 = clock();KMP_Search(sstr, slen, pstr, plen, next, res2);    cout<<"KMP 时间: "<< (double)(clock()-start2)/CLOCKS_PER_SEC*1000<<"ms"<<endl; cout<<"KMP 识别模式串个数: "<<match_kmp<<endl;cout<<"KMP 匹配次数: "<<num_kmp<<endl;cout<<"KMP 比对次数："<<bidui_kmp<<endl<<endl;
//    for(auto it : res2)
//        cout<<it<<endl;/*BMY*/int m1[ALPHABET_SIZE] = {0};int m2[ZuHe_SIZE];for(int i=0; i<ZuHe_SIZE; i++)m2[i] = -1;initP(pstr, m1, m2);vector<int> res1;clock_t start = clock();BMY(pstr, plen, sstr, slen, m1, m2, res1);cout<<"BMY 时间: "<< (double)(clock()-start)/CLOCKS_PER_SEC*1000<<"ms"<<endl; cout<<"BMY 识别模式串个数: "<<match_bmy<<endl;cout<<"BMY 匹配次数: "<<num_bmy<<endl;cout<<"BMY 比对次数："<<bidui_bmy<<endl<<endl;
//    for(auto it : res1)
//        cout<<it<<endl;/*BM*/unsigned int badc[256];  unsigned int goods[plen];BuildBadC(pstr, plen, badc, 256);  BuildGoodS(pstr_, plen, goods); vector<int> res3;clock_t start3 = clock();BM(pstr, plen, sstr, slen, badc, goods, res3);cout<<"BM 时间: "<< (double)(clock()-start3)/CLOCKS_PER_SEC*1000<<"ms"<<endl; cout<<"BM 识别模式串个数: "<<match_bm<<endl;cout<<"BM 匹配次数: "<<num_bm<<endl;cout<<"BM 比对次数："<<bidui_bm<<endl<<endl;
//    for(auto it : res3)
//        cout<<it<<endl;return 0;
}