CCF201409-3字符串匹配（KMP）

 1 #include<iostream>
 2 #include<vector>
 3 using namespace std;
 4 char str[101][101];
 5 char T[101];
 6 void NEXT(const string&T, vector<int>&next){//按模式串生成vector,next(T.size())
 7     next[0] = -1;
 8     for (int i = 1; i<T.size(); i++){
 9         int j = next[i - 1];
10         while (j >= 0 && T[i - 1] != T[j]) j = next[j];//递推计算
11         if (j >= 0 &&  T[i - 1] == T[j]) next[i] = j + 1;
12         else next[i] = 0;
13     }
14 }
15 
16 char toBig(char a){
17     if(a>=‘a‘&&a<=‘z‘){
18         a+=(‘A‘-‘a‘);
19     }
20     return a;
21 }
22 int FIND_KMP(const string&S, const string&T,int n){
23     //利用模式串T的next函数求T在主串S中是否出现的KMP算法
24     //其中T非空，
25     vector<int>next(T.size());
26     NEXT(T, next);
27     int index, count = 0;
28     for (index = 0; index<S.size(); ++index){
29         int pos = 0;
30         int iter = index;
31         while (pos<T.size() && iter<S.size()){
32            if(n==0){//不分大小写 
33                 if(toBig(S[iter])== toBig(T[pos])){ ++iter; ++pos; }
34              else{
35                 if (pos == 0) ++iter;
36                 else pos = next[pos - 1] + 1;
37             }
38            }else{//区分大小写 
39                    if (S[iter] == T[pos]){ ++iter; ++pos; }
40                  else{
41                 if (pos == 0) ++iter;
42                 else pos = next[pos - 1] + 1;
43             }
44            }
45         }
46         if (pos == T.size() && (iter - index) == T.size())// ++count;
47         {
48         count=1;
49         break;
50         }
51     }
52     return count;
53 }
54  
55 int main()
56 {
57     int n,i,m;
58     cin >> T;
59     cin>>n>>m;
60     for(i=0;i<m;i++){
61         cin>>str[i];
62     }
63     for(i=0;i<m;i++){
64         if(FIND_KMP(str[i], T,n))
65             cout<<str[i]<<endl;
66     }
67     return 0;
68 }