Best Poker Hand

CMakeLists.txt

@@ -50,6 +50,7 @@ add_task(backspace-string-compare)
 add_task(balanced-binary-tree)
 add_task(basic-calculator)
 add_task(basic-calculator-ii)
+add_task(best-poker-hand)
 add_task(best-sightseeing-pair)
 add_task(best-time-to-buy-and-sell-stock)
 add_task(best-time-to-buy-and-sell-stock-ii)

solutions/best-poker-hand/CMakeLists.txt

@@ -0,0 +1 @@
+add_catch(test_best_poker_hand test.cpp)

solutions/best-poker-hand/solution.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+class Solution {
+public:
+  static std::string bestHand(const std::vector<int> &ranks,
+                              const std::vector<char> &suits) {
+    if (std::set(suits.begin(), suits.end()).size() == 1) {
+      return "Flush";
+    }
+
+    std::map<int, int> count;
+    int max = 0;
+    for (auto r : ranks) {
+      max = std::max(max, ++count[r]);
+    }
+    if (max > 2) {
+      return "Three of a Kind";
+    }
+    if (max > 1) {
+      return "Pair";
+    }
+    return "High Card";
+  }
+};

solutions/best-poker-hand/test.cpp

@@ -0,0 +1,34 @@
+#include <catch.hpp>
+
+#include <solution.hpp>
+
+TEST_CASE("Simple") {
+  struct TestCase {
+    std::vector<int> ranks;
+    std::vector<char> suits;
+    std::string expected;
+  };
+
+  std::vector<TestCase> test_cases{
+      {
+          .ranks{13, 2, 3, 1, 9},
+          .suits{'a', 'a', 'a', 'a', 'a'},
+          .expected = "Flush",
+      },
+      {
+          .ranks{4, 4, 2, 4, 4},
+          .suits{'d', 'a', 'a', 'b', 'c'},
+          .expected = "Three of a Kind",
+      },
+      {
+          .ranks{10, 10, 2, 12, 9},
+          .suits{'a', 'b', 'c', 'a', 'd'},
+          .expected = "Pair",
+      },
+  };
+
+  for (const auto &[ranks, suits, expected] : test_cases) {
+    const auto actual = Solution::bestHand(ranks, suits);
+    REQUIRE(expected == actual);
+  }
+}