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  • bm和kmp和bf

      1 #include<iostream>
  2 #include<string>
  3 #include<vector>
  4 #include<map>
  5 #include<text.hpp>
  6 #include<ctime>
  7 
  8 using namespace std;
  9 clock_t begin, end;
 10 
 11 template<typename C, typename I>struct Map {
 12     Map() = default;
 13     vector<C>vecC;
 14     vector<I>vecI;
 15     void insert(C c, I i) {
 16         vecC.push_back(c);
 17         vecI.push_back(i);
 18     }
 19     void traverse()
 20     {
 21         for (size_t i = 0; i < vecC.size(); ++i) {
 22             cout << vecC[i] << " "<<vecI[i]<<ends;
 23         }
 24     }
 25     auto find(I i) 
 26     {
 27         return vecI.begin() + i;
 28     }
 29     
 30 };
 31 Map<char, int> create_next(const string& Pattern);
 32 
 33 int kmp_index(const string& Text, const string& Pattern) {
 34     clock_t begin = clock();
 35     auto mymap=create_next(Pattern);
 36     int hadmatched = 0;
 37     if (Text.size() < Pattern.size())return -1;
 38     size_t Tofi = 0; size_t Pofj = 0;
 39     while (Tofi < Text.size() && Pofj < Pattern.size())
 40     {
 41         
 42         if (Text[Tofi] != Pattern[Pofj]&&!hadmatched)
 43             Tofi++;
 44         else if(Text[Tofi] == Pattern[Pofj])
 45         {
 46             Tofi++;
 47             Pofj++;
 48             hadmatched++;
 49         }
 50         else if (Text[Tofi] != Pattern[Pofj] && hadmatched)
 51         {
 52             /*cout << "pofj"<<Pofj << endl;
 53             cout << "had"<<hadmatched << endl;*/
 54             Pofj -= hadmatched - *mymap.find(hadmatched - 1);
 55             hadmatched= Pofj;
 56         }
 57         
 58 
 59     }
 60     clock_t end=clock();
 61     cout << static_cast<double>(end - begin)<<"毫秒"<< endl;
 62     if (Pofj == Pattern.size())
 63         return Tofi-Pattern.size();
 64     else return -1;
 65 }
 66 Map<char,int> create_next(const string& Pattern){
 67     Map<char, int>m;
 68     size_t size = Pattern.size();
 69     for (auto i : Pattern)
 70         m.insert(i,0);
 71     for (size_t i = 0; i < size; ++i) {
 72         string begin, end = "";
 73         for (size_t j = 0; j < i; ++j) {
 74             begin += Pattern[j];
 75             end =Pattern[i-j]+end;
 76             if(begin==end)
 77             {
 78                 *m.find(i)=begin.size();
 79             }
 80         }
 81 }
 82     return m;
 83 }
 84 
 85 
 86 int bf_index(const string& Text, const string& Pattern) {
 87     clock_t begin=clock();
 88     if (Text.size() < Pattern.size())return -1;
 89     size_t Tofi = 0; size_t Pofj = 0;
 90     while (Tofi < Text.size() && Pofj < Pattern.size())
 91     {
 92         if (Text[Tofi] == Pattern[Pofj])
 93         {
 94             Tofi++;
 95             Pofj++;
 96         }
 97         else if (Text[Tofi] != Pattern[Pofj])
 98         {
 99             Tofi = Tofi - Pofj + 1;
100             Pofj = 0;
101         }
102     }
103     clock_t end=clock();
104     cout << static_cast<double>(end - begin)<<"毫秒" << endl;
105     if (Pofj == Pattern.size())
106         return Tofi - Pattern.size();
107     else return -1;
108 }
109 
110 int bm_index(const string& Text, const string& Pattern) {
111     clock_t begin = clock();
112     if (Text.size() < Pattern.size())return -1;
113     size_t Tofi = Pattern.size()-1; size_t Pofj = Tofi;
114     s:while (Tofi <= Text.size() && Pofj >0) {
115     /*    cout << Tofi<< " " << Pofj << endl;
116         cout << Text[Tofi] << " " << Pattern[Pofj] << endl;*/
117         if (Text[Tofi] == Pattern[Pofj]) {
118             Tofi--;
119             Pofj--;
120         }
121         else {
122             auto cp = Text[Tofi];
123             size_t times = 0;
124             for (size_t i = Pofj; i > 0; --i) {
125                 times++;
126                 if (cp == Pattern[i])
127                 {
128                     Tofi+=times-1;
129                         goto s;
130                 }
131             }
132                 Tofi += Pattern.size();
133                 Pofj = Pattern.size()-1;
134         }
135     }
136     clock_t end = clock();
137     cout << static_cast<double>(end - begin) << "毫秒" << endl;
138     if (Pofj == 0)
139         return Tofi;
140     else return -1;
141 }
142 
143 inline void print(int i,const string &s2,const string & s){
144     if (i == -1) { cout << "查找失败"; }
145     else {
146         cout << "字符串第" << i + 1 << "位" << endl;
147         for (size_t j = 0; j < s.size(); ++j) {
148             cout << s2[i + j];
149         }
150     }
151     cout << "匹配字符串共" << s2.size() << "位" << endl;
152 }
153 
154 int main() {
155     text(10000000).creat("random_1.txt");
156     /*string s="EXAMPLE";
157     string s2="HERE IS A SIMPLE EXAMPLQ EXAMPLE";*/
158     string s,s2;
159     cin >> s;
160     ifstream iff("random_1.txt");
161     iff >> s2;
162     
163     cout << "bm算法" << endl;
164     int i = bm_index(s2, s);
165     print(i,s2,s);
166     cout << "kmp算法" << endl;
167     int j = kmp_index(s2, s);
168     print(j,s2,s);
169     cout << "bf算法" << endl;
170     int z = bf_index(s2, s);
171     print(z,s2,s);
172     
173     
174     
175 }

    bm

    kmp&bf

    更新，写错了 size_t 会把比较的-1变成正数找了半天bug

      1 #include<iostream>
  2 #include<string>
  3 #include<vector>
  4 #include<map>
  5 #include<text.hpp>
  6 #include<ctime>
  7 
  8 using namespace std;
  9 clock_t begin, end;
 10 
 11 template<typename C, typename I>struct Map {
 12     Map() = default;
 13     vector<C>vecC;
 14     vector<I>vecI;
 15     void insert(C c, I i) {
 16         vecC.push_back(c);
 17         vecI.push_back(i);
 18     }
 19     void traverse()
 20     {
 21         for (size_t i = 0; i < vecC.size(); ++i) {
 22             cout << vecC[i] << " " << vecI[i] << ends;
 23         }
 24     }
 25     auto find(I i)
 26     {
 27         return vecI.begin() + i;
 28     }
 29 
 30 };
 31 Map<char, int> create_next(const string& Pattern);
 32 
 33 int kmp_index(const string& Text, const string& Pattern) {
 34     clock_t begin = clock();
 35     auto mymap = create_next(Pattern);
 36     int hadmatched = 0;
 37     if (Text.size() < Pattern.size())return -1;
 38     size_t Tofi = 0; size_t Pofj = 0;
 39     while (Tofi < Text.size() && Pofj < Pattern.size())
 40     {
 41 
 42         if (Text[Tofi] != Pattern[Pofj] && !hadmatched)
 43             Tofi++;
 44         else if (Text[Tofi] == Pattern[Pofj])
 45         {
 46             Tofi++;
 47             Pofj++;
 48             hadmatched++;
 49         }
 50         else if (Text[Tofi] != Pattern[Pofj] && hadmatched)
 51         {
 52             /*cout << "pofj"<<Pofj << endl;
 53             cout << "had"<<hadmatched << endl;*/
 54             Pofj -= hadmatched - *mymap.find(hadmatched - 1);
 55             hadmatched = Pofj;
 56         }
 57 
 58 
 59     }
 60     clock_t end = clock();
 61     cout << static_cast<double>(end - begin) << "毫秒" << endl;
 62     if (Pofj == Pattern.size())
 63         return Tofi - Pattern.size();
 64     else return -1;
 65 }
 66 Map<char, int> create_next(const string& Pattern) {
 67     Map<char, int>m;
 68     size_t size = Pattern.size();
 69     for (auto i : Pattern)
 70         m.insert(i, 0);
 71     for (size_t i = 0; i < size; ++i) {
 72         string begin, end = "";
 73         for (size_t j = 0; j < i; ++j) {
 74             begin += Pattern[j];
 75             end = Pattern[i - j] + end;
 76             if (begin == end)
 77             {
 78                 *m.find(i) = begin.size();
 79             }
 80         }
 81     }
 82     return m;
 83 }
 84 
 85 
 86 int bf_index(const string& Text, const string& Pattern) {
 87     clock_t begin = clock();
 88     if (Text.size() < Pattern.size())return -1;
 89     size_t Tofi = 0; size_t Pofj = 0;
 90     while (Tofi < Text.size() && Pofj < Pattern.size())
 91     {
 92         if (Text[Tofi] == Pattern[Pofj])
 93         {
 94             Tofi++;
 95             Pofj++;
 96         }
 97         else if (Text[Tofi] != Pattern[Pofj])
 98         {
 99             Tofi = Tofi - Pofj + 1;
100             Pofj = 0;
101         }
102     }
103     clock_t end = clock();
104     cout << static_cast<double>(end - begin) << "毫秒" << endl;
105     if (Pofj == Pattern.size())
106         return Tofi - Pattern.size();
107     else return -1;
108 }
109 
110 int bm_index(const string& Text, const string& Pattern) {
111     clock_t begin = clock();
112     if (Text.size() < Pattern.size())return -1;
113     int Tofi = Pattern.size() - 1; int Pofj = Tofi;
114 s:while (Tofi <= static_cast<int>(Text.size()) && Pofj >-1) {
115         /*cout << Tofi<< " " << Pofj << endl;
116         cout << Text[Tofi] << " " << Pattern[Pofj] << endl;*/
117     if (Text[Tofi] == Pattern[Pofj]) {
118         Tofi--;
119         Pofj--;
120     }
121     else {
122         auto cp = Text[Tofi];
123         bool flag=false;
124         size_t times = 0;
125         for (int i = Pofj; i>=0; --i) {
126             times++;
127             if (cp == Pattern[i])
128             {
129                 flag = true;
130                 Tofi += times - 1;
131                 goto s;
132             }
133         }
134         //cout << "times" << times << endl;
135             Tofi += Pattern.size();
136         Pofj = Pattern.size() - 1;
137     }
138 }
139 clock_t end = clock();
140 cout << static_cast<double>(end - begin) << "毫秒" << endl;
141 if (Pofj == -1)
142 return ++Tofi;
143 else return -1;
144 }
145 
146 inline void print(int i, const string& s2, const string& s) {
147     if (i == -1) { cout << "查找失败"; }
148     else {
149         cout << "字符串第" << i + 1 << "位" << endl;
150         
151         for (size_t j = 0; j < s.size(); ++j) {
152             cout << s2[i + j];
153         }
154     }
155     cout << "匹配字符串共" << s2.size() << "位" << endl;
156 }
157 
158 int main() {
159     //text(10000000).creat("random_1.txt");
160    /* string s=" alt";
161     string s2="klt clt alt oel sihadhai.jsiajsiajdaduhudsa,,siajisaSAHDIA";*/
162    string s, s2;
163     cin >> s;
164     ifstream iff("random_1.txt");
165     iff >> s2;
166 
167     cout << "bm算法" << endl;
168     int i = bm_index(s2, s);
169     print(i, s2, s);
170     cout << "kmp算法" << endl;
171     int j = kmp_index(s2, s);
172     print(j, s2, s);
173     cout << "bf算法" << endl;
174     int z = bf_index(s2, s);
175     print(z, s2, s);
176 
177 
178 
179 }
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  • 原文地址：https://www.cnblogs.com/otakus/p/kmp.html
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