Trie字符串统计

#include <bits/stdc++.h>

using namespace std;
const int N = 1e6 + 10, INF = 0x3f3f3f3f, MOD = 998244353;
int n, son[N][30], cnt[N], idx;
char str[N];

void insert(char *str) {
    int p = 0;
    for (int i = 0; str[i]; ++i) {
        int u = str[i] - 'a';
        if (!son[p][u]) son[p][u] = ++idx;
        p = son[p][u];
    }
    cnt[p]++;
}

int query(char *str) {
    int p = 0;
    for (int i = 0; str[i]; i++) {
        int u = str[i] - 'a';
        if (!son[p][u]) return 0;
        p = son[p][u];
    }
    return cnt[p];
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    cin >> n;
    while (n--) {
        char op;
        cin >> op >> str;
        if (op == 'I') insert(str);
        else cout << query(str) << endl;
    }
    return 0;
}