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

Author: Gonzalo Diaz

docs/hackerrank/warmup/birthday_cake_candles.md

@@ -0,0 +1,54 @@
+# [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.h

@@ -0,0 +1,14 @@
+#include <vector>
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int HACKERRANK_WARMUP_birthdayCakeCandles(int candles_count,
+                                          const int *candles);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif

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

@@ -0,0 +1,23 @@
+#include <exercises/hackerrank/warmup/a_very_big_sum.h>
+
+/**
+ * @link Problem definition [[docs/hackerrank/warmup/birthday_cake_candles.md]]
+ */
+
+int HACKERRANK_WARMUP_birthdayCakeCandles(int candles_count,
+                                          const int *candles) {
+  int counter = 0;
+  int maximum = candles[0];
+
+  for (int i = 0; i < candles_count; i++) {
+    if (candles[i] == maximum) {
+      counter += 1;
+    }
+    if (candles[i] > maximum) {
+      maximum = candles[i];
+      counter = 1;
+    }
+  }
+
+  return counter;
+}

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

@@ -0,0 +1,33 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include <exercises/hackerrank/warmup/birthday_cake_candles.h>
+#include <iostream>
+#include <vector>
+
+#include <filesystem>
+#include <fstream>
+#include <nlohmann/json.hpp>
+using json = nlohmann::json;
+
+TEST_CASE("birthdayCakeCandles JSON Test Cases",
+          "[hackerrank] [jsontestcase] [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) {
+    auto input_size = static_cast<int>(testcase["input"].size());
+    std::vector<int> input_vector = testcase["input"];
+    const int *input_array = input_vector.data();
+
+    long result =
+        HACKERRANK_WARMUP_birthdayCakeCandles(input_size, input_array);
+    CHECK(result == testcase["expected"]);
+  }
+}

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

@@ -0,0 +1,4 @@
+[
+  {"input": [3, 2, 1, 3], "expected": 2},
+  {"input": [1, 2, 3, 3], "expected": 2}
+]