Trie

#include <bits/stdc++.h>
#define CH (*s - 'a')

using namespace std;

ifstream fin ("trie.in");
ofstream fout ("trie.out");

struct Trie {
    int cnt, nrfii;
    Trie *fiu[26];
    Trie() {
        cnt = nrfii = 0;
        memset(fiu, 0, sizeof(fiu));
    }
};

Trie* T = new Trie;

void Insert(Trie *nod, char *s) {
    if(*s == '\n') {
        ++nod -> cnt;
        return;
    }
    if(nod -> fiu[CH] == 0) {
        nod -> fiu[CH] = new Trie;
        ++nod -> nrfii;
    }
    Insert(nod -> fiu[CH], s + 1);
}

bool Delete(Trie *nod, char *s) {
    if(*s == '\n')
        --nod -> cnt;
    else
        if(Delete(nod -> fiu[CH], s + 1)) {
            nod -> fiu[CH] = 0;
            --nod -> nrfii;
        }
    if(nod -> cnt == 0 && nod -> nrfii == 0 && nod != T) {
        delete nod;
        return true;
    }
    return false;
}

int Count(Trie *nod, char *s) {
    if(*s == '\n')
        return nod -> cnt;
    if(nod -> fiu[CH])
        return Count(nod -> fiu[CH], s + 1);
    return 0;
}

int Preffix(Trie *nod, char *s, int k) {
    if(*s == '\n' || nod -> fiu[CH] == 0)
        return k;
    return Preffix(nod -> fiu[CH], s + 1, k + 1);
}

int main() {
    short op;
    char s[32];
    while(fin >> op) {
        fin >> s;
        s[strlen(s)] = '\n';
        if(op == 0)
            Insert(T, s);
        if(op == 1)
            Delete(T, s);
        if(op == 2)
            fout << Count(T, s) << '\n';
        if(op == 3)
            fout << Preffix(T, s, 0) << '\n';
    }
}