1 int* Getnext(char *p,int len_p){//p为模式串
2 int *Next = new int[len_p];
3 Next[0] = -1;
4 int j = -1,i=0;
5 while(i < len_p){//自身与自身匹配
6 while(j != -1&&p[j]!=p[i])//移动匹配串
7 j = Next[j];
8 j+=1;
9 Next[++i] = j;
10 }
11 return Next;
12 }
13 vector<int>* Kmp(char *s,char *p,int len_s,int len_p){//s为主串,p为匹配串
14 int *Next = Getnext(p,len_p);//求得Next数组
15 int j = 0;//j为匹配串匹配到的位置
16 vector<int>* ans = new vector<int>();//ans为匹配到的主串的开头下标位置
17 for(int i=0;i < len_s;i++){
18 while(j != -1 && s[i] != p[j])
19 j = Next[j];
20 j+=1;
21 if(j == len_p){//匹配串匹配完毕
22 ans->push_back(i - len_p + 1);
23 j = Next[j];//j退回到Next[j]
24 }
25 }
26 return ans;
27 }
