httpjson.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

class Solution {
    
    /* provided template code above. discouraged from editing, so we're not expected
       to need System.Threading.Tasks. */

    /*
    * Complete the function below.
    * https://jsonmock.hackerrank.com/api/countries/search?name=
    */
    static int getCountries(string s, int p) {
        var count = 0;
        var baseUrl = $"https://jsonmock.hackerrank.com/api/countries/search?name={s}";
        using (var httpClient = new HttpClient())
        {
            var json = httpClient.GetStringAsync(baseUrl).Result;
            var obj = JObject.Parse(json);
            var totalPages = (int)obj["total_pages"];
            count += obj["data"].Count(x => (long)x["population"] > p);

            var countTasks = new List<System.Threading.Tasks.Task<int>>();
            for (var page = 2; page <= totalPages; page++)
            {
                var url = $"{baseUrl}&page={page}";
                // i tried a few different combinations here. Task.Run doesn't make sense for I/O bound operations
                // but it seemed to timeout less anyway (??)
                countTasks.Add(System.Threading.Tasks.Task.Run(() => httpClient.GetStringAsync(url).ContinueWith(antecedent =>
                {
                    var obj2 = JObject.Parse(antecedent.Result);
                    return obj2["data"].Count(x => (long)x["population"] > p);
                })));
            }

            foreach (var countTask in countTasks)
            {
                count += countTask.Result;
            }
        }
        return count;
    }
    /* provided template code below. discouraged from editing, so we're not expected
       to make it an async function. */

    static void Main(String[] args) {
        string fileName = System.Environment.GetEnvironmentVariable("OUTPUT_PATH");
        TextWriter tw = new StreamWriter(@fileName, true);
        int res;
        string _s;
        _s = Console.ReadLine();
        
        int _p;
        _p = Convert.ToInt32(Console.ReadLine());
        
        res = getCountries(_s, _p);
        tw.WriteLine(res);
        
        tw.Flush();
        tw.Close();
    }
}