[Hacker Rank]: Warmup: Birthday Cake Candles solved ✅

Author: Gonzalo Diaz

docs/hackerrank/warmup/birthday_cake_candles.md

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+# [Birthday Cake Candles](https://www.hackerrank.com/challenges/birthday-cake-candles)
+
+Difficulty: #easy
+Category: #warmup
+
+You are in charge of the cake for a child's birthday.
+You have decided the cake will have one candle for each year of their total
+age. They will only be able to blow out the tallest of the candles.
+Count how many candles are tallest.
+
+## Example
+
+The maximum height candles are 4 units high.
+There are 2 of them, so return 2.
+
+## Function Description
+
+Complete the function birthdayCakeCandles in the editor below.
+birthdayCakeCandles has the following parameter(s):
+
+- int candles[n]: the candle heights
+
+## Returns
+
+- int: the number of candles that are tallest
+
+## Input Format
+
+The first line contains a single integer, n, the size of candles[].
+The second line contains  space-separated integers, where each integer i describes
+the height of candles[i].
+
+## Constraints
+
+$ 1 \leq n \leq 10^5 $
+$ 1 \leq candles[i] \leq 10^7 $
+
+## Sample Input 0
+
+```text
+4
+3 2 1 3
+```
+
+## Sample Output 0
+
+```text
+2
+```
+
+## Explanation 0
+
+Candle heights are $ [3, 2, 1, 3] $. The tallest candles are $ 3 $ units, and there
+are $ 2 $ of them.

src/lib/exercises/include/exercises/hackerrank/warmup/birthday_cake_candles.hpp

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+#include <vector>
+
+#pragma once
+
+namespace hackerrank::warmup {
+    int birthdayCakeCandles(const std::vector<int>& candles);
+}

src/lib/exercises/src/hackerrank/warmup/birthday_cake_candles.cpp

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+#include <exercises/hackerrank/warmup/a_very_big_sum.hpp>
+
+/**
+ * @link Problem definition [[docs/hackerrank/warmup/birthday_cake_candles.md]]
+ */
+
+#include <numeric>
+#include <vector>
+
+namespace hackerrank::warmup {
+
+    int birthdayCakeCandles(const std::vector<int>& candles) {
+
+        int counter = 0;
+        int maximum = candles[0];
+
+        for (const int& element : candles) {
+            if (element == maximum) {
+                counter += 1;
+            }
+            if (element > maximum) {
+                maximum = element;
+                counter = 1;
+            }
+        }
+
+        return counter;
+    }
+
+}

src/tests/unit/lib/hackerrank/warmup/birthday_cake_candles.cpp

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+#include <catch2/catch_test_macros.hpp>
+
+#include <exercises/hackerrank/warmup/birthday_cake_candles.hpp>
+#include <iostream>
+#include <vector>
+
+#include <filesystem>
+#include <fstream>
+#include <nlohmann/json.hpp>
+using json = nlohmann::json;
+
+TEST_CASE("birthdayCakeCandles JSON Test Cases", "[warmup]")
+{
+    std::filesystem::path cwd = std::filesystem::current_path();
+    std::string path = cwd.string() + "/unit/lib/hackerrank/warmup/birthday_cake_candles.testcases.json";
+
+    INFO("birthdayCakeCandles JSON test cases FILE: " << path);
+
+    std::ifstream f(path);
+    json data = json::parse(f);
+
+    for (auto testcase : data) {
+        long result = hackerrank::warmup::birthdayCakeCandles(testcase["input"]);
+        CHECK(result == testcase["expected"]);
+    }
+}

src/tests/unit/lib/hackerrank/warmup/birthday_cake_candles.testcases.json

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+[
+  {"input": [3, 2, 1, 3], "expected": 2},
+  {"input": [1, 2, 3, 3], "expected": 2}
+]