URI 1254 Tag replacement

#include <bits/stdc++.h>

#define db(x) cerr << #x << ': ' << x << endl;

using namespace std;

int main(){
    string word, newer, ans;
    while (getline(cin, word)){
        stringstream final;
        getline(cin, newer);
        getline(cin, ans);
        bool ok = false, tag = false;
        for (int i = 0; i < ans.length(); i++){
            if (ans[i] == '<'){
                tag = true;
            }else{
                if (ans[i] == '>')
                    tag = false;
            }
            if (tolower(ans[i]) == tolower(word[0]) && tag){
                ok = true;
                for (int j = i+1, h = 1; h < word.length(); j++, h++){
                    if (tolower(ans[j]) != tolower(word[h])){
                        ok = false;
                        break;
                    }
                }
                if (ok){
                    final << newer;
                    i += (word.length() - 1);
                }else{
                    final << ans[i];
                }
            }else{
                final << ans[i];
            }
        }
        cout << final.str() << endl; // remplaza todas las ocurrencias
    }
    return 0;
}