ContextQMD
Back to Freecodecamp

Challenge 196: 2026 Winter Games Day 17: Closing Day

curriculum/challenges/english/blocks/daily-coding-challenges-python/697a49e9860d24853adef681.md

latest5.8 KB
Original Source

--description--

Given a 2D array of medal winners, return a medal count for each country as a CSV string.

  • In the given array, each sub-array represents a single event: [gold_winner, silver_winner, bronze_winner]

  • The returned CSV string should have the following format, with the first line being headers:

sh
Country,Gold,Silver,Bronze,Total
country_name,gold_count,silver_count,bronze_count,total_medals
  • Separate new lines with the new line character ("\n").
  • Do not include spaces around commas or at the end of lines.
  • Sort the returned CSV by gold medal count, highest first. If two countries have the same gold medal count, sort the tied ones alphabetically.

For example, given:

js
[
  ["USA", "CAN", "NOR"],
  ["NOR", "USA", "CAN"],
  ["USA", "NOR", "SWE"]
]

Return:

sh
"Country,Gold,Silver,Bronze,Total\nUSA,2,1,0,3\nNOR,1,1,1,3\nCAN,0,1,1,2\nSWE,0,0,1,1"

Which looks like this when printed:

sh
Country,Gold,Silver,Bronze,Total
USA,2,1,0,3
NOR,1,1,1,3
CAN,0,1,1,2
SWE,0,0,1,1

--hints--

count_medals([["USA", "CAN", "NOR"], ["NOR", "USA", "CAN"], ["USA", "NOR", "SWE"]]) should return "Country,Gold,Silver,Bronze,Total\nUSA,2,1,0,3\nNOR,1,1,1,3\nCAN,0,1,1,2\nSWE,0,0,1,1".

js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(count_medals([["USA", "CAN", "NOR"], ["NOR", "USA", "CAN"], ["USA", "NOR", "SWE"]]), "Country,Gold,Silver,Bronze,Total\\nUSA,2,1,0,3\\nNOR,1,1,1,3\\nCAN,0,1,1,2\\nSWE,0,0,1,1")`)
}})

count_medals([["NOR","SWE","FIN"]]) should return "Country,Gold,Silver,Bronze,Total\nNOR,1,0,0,1\nFIN,0,0,1,1\nSWE,0,1,0,1".

js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(count_medals([["NOR","SWE","FIN"]]), "Country,Gold,Silver,Bronze,Total\\nNOR,1,0,0,1\\nFIN,0,0,1,1\\nSWE,0,1,0,1")`)
}})

count_medals([["ITA", "CHN", "CHN"], ["JPN", "ITA", "JPN"]]) should return "Country,Gold,Silver,Bronze,Total\nITA,1,1,0,2\nJPN,1,0,1,2\nCHN,0,1,1,2".

js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(count_medals([["ITA", "CHN", "CHN"], ["JPN", "ITA", "JPN"]]), "Country,Gold,Silver,Bronze,Total\\nITA,1,1,0,2\\nJPN,1,0,1,2\\nCHN,0,1,1,2")`)
}})

count_medals([["USA","CAN","NOR"], ["GER","FRA","ITA"], ["JPN","KOR","CHN"], ["SWE","FIN","NOR"], ["CAN","USA","SWE"], ["FRA","GER","ITA"]]) should return "Country,Gold,Silver,Bronze,Total\nCAN,1,1,0,2\nFRA,1,1,0,2\nGER,1,1,0,2\nJPN,1,0,0,1\nSWE,1,0,1,2\nUSA,1,1,0,2\nCHN,0,0,1,1\nFIN,0,1,0,1\nITA,0,0,2,2\nKOR,0,1,0,1\nNOR,0,0,2,2".

js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(count_medals([["USA","CAN","NOR"], ["GER","FRA","ITA"], ["JPN","KOR","CHN"], ["SWE","FIN","NOR"], ["CAN","USA","SWE"], ["FRA","GER","ITA"]]), "Country,Gold,Silver,Bronze,Total\\nCAN,1,1,0,2\\nFRA,1,1,0,2\\nGER,1,1,0,2\\nJPN,1,0,0,1\\nSWE,1,0,1,2\\nUSA,1,1,0,2\\nCHN,0,0,1,1\\nFIN,0,1,0,1\\nITA,0,0,2,2\\nKOR,0,1,0,1\\nNOR,0,0,2,2")`)
}})

count_medals([["ESP","ITA","FRA"], ["ITA","ESP","GER"], ["NOR","SWE","FIN"], ["FIN","NOR","SWE"], ["USA","CAN","MEX"], ["CAN","USA","MEX"], ["JPN","KOR","CHN"], ["CHN","JPN","KOR"]]) should return "Country,Gold,Silver,Bronze,Total\nCAN,1,1,0,2\nCHN,1,0,1,2\nESP,1,1,0,2\nFIN,1,0,1,2\nITA,1,1,0,2\nJPN,1,1,0,2\nNOR,1,1,0,2\nUSA,1,1,0,2\nFRA,0,0,1,1\nGER,0,0,1,1\nKOR,0,1,1,2\nMEX,0,0,2,2\nSWE,0,1,1,2".

js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(count_medals([["ESP","ITA","FRA"], ["ITA","ESP","GER"], ["NOR","SWE","FIN"], ["FIN","NOR","SWE"], ["USA","CAN","MEX"], ["CAN","USA","MEX"], ["JPN","KOR","CHN"], ["CHN","JPN","KOR"]]), "Country,Gold,Silver,Bronze,Total\\nCAN,1,1,0,2\\nCHN,1,0,1,2\\nESP,1,1,0,2\\nFIN,1,0,1,2\\nITA,1,1,0,2\\nJPN,1,1,0,2\\nNOR,1,1,0,2\\nUSA,1,1,0,2\\nFRA,0,0,1,1\\nGER,0,0,1,1\\nKOR,0,1,1,2\\nMEX,0,0,2,2\\nSWE,0,1,1,2")`)
}})

count_medals([["USA","CAN","GER"], ["NOR","SWE","FIN"], ["USA","NOR","SWE"], ["GER","FRA","ITA"], ["JPN","KOR","CHN"], ["USA","GER","CAN"], ["SWE","NOR","FIN"], ["CAN","USA","NOR"], ["FRA","GER","ITA"], ["JPN","CHN","KOR"], ["SWE","FIN","NOR"], ["GER","ITA","FRA"]]) should return "Country,Gold,Silver,Bronze,Total\nUSA,3,1,0,4\nGER,2,2,1,5\nJPN,2,0,0,2\nSWE,2,1,1,4\nCAN,1,1,1,3\nFRA,1,1,1,3\nNOR,1,2,2,5\nCHN,0,1,1,2\nFIN,0,1,2,3\nITA,0,1,2,3\nKOR,0,1,1,2".

js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(count_medals([["USA","CAN","GER"], ["NOR","SWE","FIN"], ["USA","NOR","SWE"], ["GER","FRA","ITA"], ["JPN","KOR","CHN"], ["USA","GER","CAN"], ["SWE","NOR","FIN"], ["CAN","USA","NOR"], ["FRA","GER","ITA"], ["JPN","CHN","KOR"], ["SWE","FIN","NOR"], ["GER","ITA","FRA"]]), "Country,Gold,Silver,Bronze,Total\\nUSA,3,1,0,4\\nGER,2,2,1,5\\nJPN,2,0,0,2\\nSWE,2,1,1,4\\nCAN,1,1,1,3\\nFRA,1,1,1,3\\nNOR,1,2,2,5\\nCHN,0,1,1,2\\nFIN,0,1,2,3\\nITA,0,1,2,3\\nKOR,0,1,1,2")`)
}})

--seed--

--seed-contents--

py
def count_medals(winners):

    return winners

--solutions--

py
def count_medals(winners):
    counts = {}

    for gold, silver, bronze in winners:
        for country, medal_type in [(gold, "Gold"), (silver, "Silver"), (bronze, "Bronze")]:
            if country not in counts:
                counts[country] = {"Gold": 0, "Silver": 0, "Bronze": 0}
            counts[country][medal_type] += 1

    countries = [
        {
            "Country": country,
            "Gold": medals["Gold"],
            "Silver": medals["Silver"],
            "Bronze": medals["Bronze"],
            "Total": medals["Gold"] + medals["Silver"] + medals["Bronze"]
        }
        for country, medals in counts.items()
    ]

    countries.sort(key=lambda c: (-c["Gold"], c["Country"]))

    lines = ["Country,Gold,Silver,Bronze,Total"]
    for c in countries:
        lines.append(f'{c["Country"]},{c["Gold"]},{c["Silver"]},{c["Bronze"]},{c["Total"]}')

    return "\n".join(lines)