s0038

include/s0038_count_and_say.hpp

@@ -0,0 +1,14 @@
+#ifndef S0038_COUNT_AND_SAY_HPP
+#define S0038_COUNT_AND_SAY_HPP
+
+#include <string>
+#include <algorithm>
+
+using namespace std;
+
+class Solution {
+ public:
+  string countAndSay(int n);
+};
+
+#endif

src/s0038_count_and_say.cpp

@@ -0,0 +1,21 @@
+#include "s0038_count_and_say.hpp"
+
+string Solution::countAndSay(int n) {
+  if (n == 1) {
+    return "1";
+  } else if (n <= 0) {
+    return "";
+  }
+  string prev = countAndSay(n - 1);
+  string result{""};
+  int len = prev.length();
+  int pos{0}, start{0};
+  while (pos < len) {
+    while (pos < len && prev[pos] == prev[start]) {
+      pos++;
+    }
+    result += to_string(pos - start) + prev[start];
+    start = pos;
+  }
+  return result;
+}

tests/s0038_count_and_say.cpp

@@ -0,0 +1,17 @@
+#include "s0038_count_and_say.hpp"
+
+#include <gtest/gtest.h>
+
+TEST(Problem38, Case1) {
+  int i{1};
+  string o{"1"};
+  Solution solution;
+  EXPECT_EQ(solution.countAndSay(i), o);
+}
+
+TEST(Problem38, Case2) {
+  int i{4};
+  string o{"1211"};
+  Solution solution;
+  EXPECT_EQ(solution.countAndSay(i), o);
+}