Codingame MIME types challenge solution in Dart

cg-mime-types

// Codingame MIME types challenge solution in Dart
// Eric Taix

import 'dart:io';

void main() {
    int nbAsso = int.parse(stdin.readLineSync());
    int nbFile = int.parse(stdin.readLineSync());
    
    Map mimes = new List.generate(nbAsso, (_) => stdin.readLineSync()).map((s) => s.split(' ')).fold({}, (r, s) => r ..[s[0].toLowerCase()] = s[1]);
    
    for (int i = 0; i < nbFile; i++) {
        String file = stdin.readLineSync();
        int index = file.lastIndexOf('.');
        String ext =  index >= 0 && index <= file.length - 2? file.substring(file.lastIndexOf('.')+1).toLowerCase() : "";
        print(mimes.containsKey(ext) ? mimes[ext] : "UNKNOWN");
    }
}