hdu5687 字典树

hdu5687

#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5+5, n = 26;
struct node {
    int next[26];
    int cnt;
    void init() {
        cnt = 0;
        memset(next,-1,sizeof(next));
    }
};
node trie[maxn*n];
int tot = 0;
void insert(char *s) {
    int cur = 0, len = strlen(s);
    for (int i = 0; i < len; i++) {
        int temp = s[i]-'a';
        int next = trie[cur].next[temp];
        if (next == -1) {
            next = ++tot;
            trie[next].init();
            trie[cur].next[temp] = next;
        }
        cur = next;
        trie[cur].cnt++;
    }
}
bool find(char *s) {
    int cur = 0, len = strlen(s);
    for (int i = 0; i < len; i++) {
        int temp = s[i]-'a';
        int next = trie[cur].next[temp];
        if (next == -1) return false;
        cur = next;
    }
    return trie[cur].cnt > 0;
}
void del(char * s) {
    int cur = 0, late, len = strlen(s);
    for (int i = 0; i < len; i++) {
        int temp = s[i]-'a';
        int next = trie[cur].next[temp];
        if (next == -1) return;
        late = cur;
        cur = next;
    }
    cur = 0;
    for (int i = 0; i < len; i++) {
        int temp = s[i]-'a';
        int next = trie[cur].next[temp];
        late = cur;
        cur = next;
        trie[cur].cnt--;
    }
    trie[cur].init();
    int temp = s[len-1]-'a';
    trie[late].next[temp] = -1;
}
int main() {
    int n; scanf("%d",&n);
    char cmd[32], word[32];
    for (int i = 1; i <= n; i++) {
        scanf("%s%s",cmd,word);
        if (cmd[0] == 'i') insert(word);
        else if (cmd[0] == 's') {
            if (find(word)) puts("Yes");
            else puts("No");
        }
        else del(word);
    }
    return 0;
}