Trie C++

#include <iostream>
#include <vector>
#include <map>

using namespace std;

int K = 26;

struct node
{
    vector<node*> child;
    bool leaf = false;
    int freq = 0;

    node()
    {
        child.assign(26, nullptr);
    }

};

node* root = new node();

void add(string s)
{
    node* cur = root;
    for(char c : s)
    {
        if(cur->child[c-'a'] == nullptr) cur->child[c-'a'] = new node();
        cur = cur->child[c-'a'];
    }
    cur->leaf = true;
    cur->freq++;
}

bool contains(string s)
{
    node* cur = root;
    for(char c : s)
    {
        if(cur->child[c-'a'] == nullptr) return false;
        cur = cur->child[c-'a'];
    }
    return true;
}

int main()
{
    add("abc");
    add("abd");
    add("bad");
    add("badc");

    cout << "Contains abd? "<<(contains("abd")?"Yes.\n":"No.\n");
    cout << "Contains badd? "<<(contains("badd")?"Yes.\n":"No.\n");

}