题目说是可见字符，ASCII码中可见字符的前面一位是' '空格，next数组大小100就可以了，字符转化成数字需要减去' '这个字符
#include<bits/stdc++.h> using namespace std; const int maxn = 1e7 + 5; const int nsize = 26; struct node { node *next[nsize]; node *fail; int sum; }; int cnt; node *root; //构造字典树 void Insert(char *s) { node *newnode,*p; p = root; for(int i = 0; s[i]; i++) { int x = s[i] - 'a'; if(p->next[x] == NULL) { newnode=(struct node *)malloc(sizeof(struct node)); for(int j=0; j<nsize; j++) newnode->next[j] = 0; newnode->sum = 0; newnode->fail = 0; p->next[x]=newnode; } p = p->next[x]; } p->sum++; } //构造失败指针 void build_fail() { queue<node*> Q; Q.push(root); while (!Q.empty()) { node *p = Q.front(); Q.pop(); for(int i = 0; i < nsize; i++) { if (p->next[i]) { if (p == root) p->next[i]->fail = p; else { node *tmp = p->fail; while (tmp) { if (tmp->next[i]) { p->next[i]->fail = tmp->next[i]; break; } else tmp = tmp->fail; } if (!tmp) p->next[i]->fail = root; } Q.push(p->next[i]); } } } return ; } //匹配 void ac_automation(char *ch) { node *p = root; int len = strlen(ch); for(int i = 0; i < len; i++) { int x = ch[i] - 'a'; while(!p->next[x] && p != root) { p = p->fail; if(p->sum > 0) { cnt += p->sum; //不想改变sun值就用vis数组标记 p->sum = -1; } } p = p->next[x]; if(!p) p = root; node *temp = p; while(temp != root) { if(temp->sum > 0) { cnt += temp->sum; temp->sum = -1; } else break; temp = temp->fail; } } } char key[70],pattern[maxn]; int main() { // freopen("Input.txt","r",stdin); int T,N; scanf("%d",&T); while(T--) { root=(struct node *)malloc(sizeof(struct node)); for(int j=0; j<nsize; j++) root->next[j] = 0; root->fail = 0; root->sum = 0; scanf("%d",&N); getchar(); for(int i = 1; i <= N; i++) { gets(key); Insert(key); } gets(pattern); cnt = 0; build_fail(); ac_automation(pattern); printf("%d ",cnt); } return 0; }