#include <iostream>
#include <string>


int main() {
    using leaf_type = std::string[2];

    leaf_type tree[5] =
    {
        {"1234", "1234-abcde"},
        {"2345", "2345-bcdef"},
        {"3456", "3456-cdefg"},
        {"4567", "4567-defgh"},
        {"5678", "5678-efghi"},
    };

    auto data = "3456";

    for (auto* current = &tree[0]; current < tree+5; ++current) 
    {
        if ((*current)[0] == data) {
            std::cout << data << " exists with value " << (*current)[1] << '\n';
            break;
        }
    }
}