unordered_map Lookups

Lab C++ Intermediate 20 points

Read n lines username id into an unordered_map, then q usernames; print each id or unknown. (Only lookups - never print an unordered map's iteration order.)

Input

n, n lines, q, q names.

Output

q lines.

Example

Input

3
ann 7
bob 12
cy 3
3
bob
zed
ann

Output

12
unknown
7

Sample input available Sample output available

Editor

C++

Hints

find returns end() when the key is missing - it doesn't insert like [].

Solution explanation

Hash maps average O(1) lookups, but their iteration order is unspecified.

Show solution

#include <iostream>
#include <string>
#include <unordered_map>
using namespace std;

int main() {
    int n, q;
    cin >> n;
    unordered_map<string, int> ids;
    for (int i = 0; i < n; i++) {
        string name;
        int id;
        cin >> name >> id;
        ids[name] = id;
    }
    cin >> q;
    for (int i = 0; i < q; i++) {
        string name;
        cin >> name;
        auto it = ids.find(name);
        if (it == ids.end()) cout << "unknown\n";
        else cout << it->second << "\n";
    }
    return 0;
}

Output

Answer