GH-194: Solve leetcode 21, 206 (#237)

Author: rain1024

collections/leetcode/README.md

@@ -31,7 +31,7 @@
 <td>19</td>
 <td>🟢&nbsp;<a href='https://github.com/rain1024/datastructures-algorithms-competitive-programming/tree/main/problems/leetcode20'>20</a></td>
 <tr>
-<td>21</td>
+<td>🟢&nbsp;<a href='https://github.com/rain1024/datastructures-algorithms-competitive-programming/tree/main/problems/leetcode21'>21</a></td>
 <td>22</td>
 <td>🔴&nbsp;<a href='https://github.com/rain1024/datastructures-algorithms-competitive-programming/tree/main/problems/leetcode23'>23</a></td>
 <td>24</td>
@@ -234,7 +234,7 @@
 <td>203</td>
 <td>204</td>
 <td>🟡&nbsp;<a href='https://github.com/rain1024/datastructures-algorithms-competitive-programming/tree/main/problems/leetcode205'>205</a></td>
-<td>206</td>
+<td>🟡&nbsp;<a href='https://github.com/rain1024/datastructures-algorithms-competitive-programming/tree/main/problems/leetcode206'>206</a></td>
 <td>207</td>
 <td>🟡&nbsp;<a href='https://github.com/rain1024/datastructures-algorithms-competitive-programming/tree/main/problems/leetcode208'>208</a></td>
 <td>209</td>

collections/leetcode/data.yaml

@@ -5,6 +5,10 @@ problems:
 - name: 20
   languages: cpp
   level: easy
+- name: 21
+  languages: cpp
+  level: easy
+  tags: linked-list, recursion
 - name: 23
   languages: cpp
   level: hard
@@ -44,6 +48,10 @@ problems:
 - name: 205
   languages: cpp
   level: medium
+- name: 206
+  languages: cpp
+  level: medium
+  tags: linked-list, recursion
 - name: 208
   languages: cpp
   level: medium

concepts/general/linked-list/README.md

@@ -41,6 +41,11 @@ SEARCHING
 * Insertion: Insert a new element at the beginning, end or in the middle of the list
 * Deletion: Delete an element from the beginning, end or in the middle of the list
 
+## Problems
+
+* [Leecode 21](https://leetcode.com/problems/merge-two-sorted-lists/)
+* [Leecode 206](https://leetcode.com/problems/reverse-linked-list/)
+
 ## 🔗 Further Reading
 
 * [Linked Lists in Python](https://realpython.com/linked-lists-python/), realpython.com

problems/leetcode206/.gitignore

@@ -0,0 +1,2 @@
+solution
+*.dSYM

problems/leetcode206/README.md

@@ -0,0 +1,19 @@
+# Leetcode Problem 
+
+## Usage
+
+Run program with an example
+
+```
+bazel run cpp/main:solution < data/1.in
+```
+
+Test program
+
+```
+# Run all tests
+bazel test --test_output=all tests:solution_test
+bazel test --test_output=all --cache_test_results=no tests:solution_test
+# Run test with pecific test id
+bazel test --test_output=all tests:solution_test --test_arg=1
+```

problems/leetcode206/cpp/main/BUILD

@@ -0,0 +1,7 @@
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+
+cc_binary(
+    name = "solution",
+    srcs = ["solution.cpp", "solution.h"],
+    visibility = ["//visibility:public"],
+)

problems/leetcode206/cpp/main/solution.cpp

@@ -0,0 +1,34 @@
+#include "solution.h"
+
+#include <algorithm>
+#include <cmath>
+#include <iostream>
+#include <map>
+#include <string>
+#include <vector>
+#include <fstream>
+
+using namespace std;
+
+int main() {
+  ios::sync_with_stdio(false);
+  cin.tie(0);
+
+  bool is_use_file = false;
+
+  filesystem::path filepath =
+      filesystem::current_path().parent_path().parent_path() / "data" / "1.in";
+  ifstream file(filepath);
+
+  if (is_use_file) {
+    cin.rdbuf(file.rdbuf());  // redirect cin to file
+  }
+
+  // get input and output
+  ListNode* head = new ListNode(1, new ListNode(2, new ListNode(3, new ListNode(4, new ListNode(5)))));
+
+  Solution solution;
+  ListNode* ans = solution.reverseList(head);
+
+  return 0;
+}

problems/leetcode206/cpp/main/solution.h

@@ -0,0 +1,33 @@
+#include <algorithm>
+#include <cmath>
+#include <map>
+#include <queue>
+#include <set>
+#include <stack>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+using namespace std;
+
+struct ListNode {
+  int val;
+  ListNode* next;
+  ListNode() : val(0), next(nullptr) {}
+  ListNode(int x) : val(x), next(nullptr) {}
+  ListNode(int x, ListNode* next) : val(x), next(next) {}
+};
+
+class Solution {
+ public:
+  ListNode* reverseList(ListNode* head) {
+    if (!head) return nullptr;
+    ListNode* ans = new ListNode(head->val);
+    ListNode* tmp = head;
+    while (tmp->next) {
+      ans = new ListNode(tmp->next->val, ans);
+      tmp = tmp->next;
+    }
+    return ans;
+  }
+};

problems/leetcode206/cpp/tests/BUILD

@@ -0,0 +1,11 @@
+load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_test")
+
+cc_test(
+    name = "solution_test",
+    srcs = ["solution_test.cpp"],
+    deps = [
+      "//problems/codeforcesAA/src/main:solution",
+      "@com_google_googletest//:gtest_main",
+    ],
+    data = ["data"]
+)

problems/leetcode206/cpp/tests/solution_test.cpp

@@ -0,0 +1,97 @@
+#include <cstdlib>
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include "gtest/gtest.h"
+
+namespace fs = std::filesystem;
+
+using namespace std;
+
+std::string TEST_ID = "";
+
+vector<string> split(string s, string delimiter) {
+  size_t pos_start = 0, pos_end, delim_len = delimiter.length();
+  string token;
+  vector<string> res;
+
+  while ((pos_end = s.find(delimiter, pos_start)) != string::npos) {
+    token = s.substr(pos_start, pos_end - pos_start);
+    pos_start = pos_end + delim_len;
+    res.push_back(token);
+  }
+
+  res.push_back(s.substr(pos_start));
+  return res;
+}
+
+std::string GetHello(std::string_view in) {
+  if (in.size() == 0) {
+    return std::string("hello, word");
+  } else {
+    return std::string("Hello, ") + in.data();
+  }
+}
+
+string ReadFile(const std::string &filename) {
+  std::ifstream f(filename);
+  string s((std::istreambuf_iterator<char>(f)),
+           std::istreambuf_iterator<char>());
+  return s;
+}
+
+vector<string> RunProgram(string fileid) {
+  vector<string> v;
+  string program = "problems/codeforcesAA/src/main/solution";
+  string test_folder = "problems/codeforcesAA/tests/data/";
+  string command = program + " < " + test_folder + fileid + ".in > output.txt";
+  std::system(command.c_str());
+  string actual = ReadFile("output.txt");
+  string expectedOutputFile = test_folder + fileid + ".out";
+  string expected = ReadFile(expectedOutputFile);
+  v.push_back(actual);
+  v.push_back(expected);
+  return v;
+}
+
+TEST(RunTest, AllTestCases) {
+  if (TEST_ID != "") {
+    std::cout << "TEST_ID = " << TEST_ID << std::endl;
+  } else {
+    std::cout << "RUN ALL TESTS" << std::endl;
+  }
+
+  std::string test_data_folder = "problems/codeforcesAA/tests/data";
+  for (const auto &entry : fs::directory_iterator(test_data_folder)) {
+    string filename = split(entry.path(), "/").back();
+    vector<string> v = split(filename, ".");
+    string fileid = v[0];
+    string extension = v[1];
+    if (extension != "in"){
+      continue;
+    }
+    if (TEST_ID != ""){
+      if (fileid != TEST_ID){
+        continue;
+      }
+    }
+    // Run Test Case
+    vector<string> output = RunProgram(fileid);
+    string actual = output[0];
+    string expected = output[1];
+    string message = "❌ FAIL CASE: " + fileid;
+    ASSERT_EQ(actual, expected) << message;
+  }
+}
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  if (argc == 2) {
+    TEST_ID = argv[1];
+  }
+  return RUN_ALL_TESTS();
+}

problems/leetcode206/data/1.in

@@ -0,0 +1 @@
+5

problems/leetcode206/data/1.out

@@ -0,0 +1,5 @@
+4
+3
+2
+1
+0

problems/leetcode206/data/2.in

@@ -0,0 +1 @@
+10

problems/leetcode206/data/2.out

@@ -0,0 +1,10 @@
+9
+8
+7
+6
+5
+4
+3
+2
+1
+0

problems/leetcode206/data/3.in

@@ -0,0 +1 @@
+3

problems/leetcode206/data/3.out

@@ -0,0 +1,3 @@
+2
+1
+0

problems/leetcode206/problem_infos.json

@@ -0,0 +1,9 @@
+{
+  "name": "Leetcode 78. Subsets",
+  "link": "https://leetcode.com/problems/subsets/",
+  "tags": [
+    "Array",
+    "Backtracking",
+    "Bit Manipulation"
+  ]
+}

problems/leetcode21/.gitignore

@@ -0,0 +1,2 @@
+solution
+*.dSYM

problems/leetcode21/README.md

@@ -0,0 +1,19 @@
+# Leetcode Problem 
+
+## Usage
+
+Run program with an example
+
+```
+bazel run cpp/main:solution < data/1.in
+```
+
+Test program
+
+```
+# Run all tests
+bazel test --test_output=all tests:solution_test
+bazel test --test_output=all --cache_test_results=no tests:solution_test
+# Run test with pecific test id
+bazel test --test_output=all tests:solution_test --test_arg=1
+```

problems/leetcode21/cpp/main/BUILD

@@ -0,0 +1,7 @@
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+
+cc_binary(
+    name = "solution",
+    srcs = ["solution.cpp", "solution.h"],
+    visibility = ["//visibility:public"],
+)

problems/leetcode21/cpp/main/solution.cpp

@@ -0,0 +1,34 @@
+#include "solution.h"
+
+#include <algorithm>
+#include <cmath>
+#include <iostream>
+#include <map>
+#include <string>
+#include <vector>
+#include <fstream>
+
+using namespace std;
+
+int main() {
+  ios::sync_with_stdio(false);
+  cin.tie(0);
+
+  bool is_use_file = false;
+
+  filesystem::path filepath =
+      filesystem::current_path().parent_path().parent_path() / "data" / "1.in";
+  ifstream file(filepath);
+
+  if (is_use_file) {
+    cin.rdbuf(file.rdbuf());  // redirect cin to file
+  }
+
+  // get input and output
+  ListNode* l1 = new ListNode(1, new ListNode(2, new ListNode(4)));
+  ListNode* l2 = new ListNode(1, new ListNode(3, new ListNode(4)));
+
+  ListNode* l = Solution().mergeTwoLists(l1, l2);
+
+  return 0;
+}