From f78d5ea3bba7ac12854f99e0cffdfb0eb83937e5 Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Wed, 30 Oct 2024 21:01:42 +0300
Subject: [PATCH 1/8] Added cyclic list (hw6 task 2)

---
 homework_6/CMakeLists.txt        |  2 +
 homework_6/task_2/CMakeLists.txt |  9 +++++
 homework_6/task_2/cyclicList.c   | 52 ++++++++++++++++++++++++++
 homework_6/task_2/cyclicList.h   | 30 +++++++++++++++
 homework_6/task_2/test.c         | 63 ++++++++++++++++++++++++++++++++
 5 files changed, 156 insertions(+)
 create mode 100644 homework_6/task_2/CMakeLists.txt
 create mode 100644 homework_6/task_2/cyclicList.c
 create mode 100644 homework_6/task_2/cyclicList.h
 create mode 100644 homework_6/task_2/test.c

diff --git a/homework_6/CMakeLists.txt b/homework_6/CMakeLists.txt
index 1431304..2b83e01 100644
--- a/homework_6/CMakeLists.txt
+++ b/homework_6/CMakeLists.txt
@@ -1,3 +1,5 @@
 project(homework_6)
 
 set(homeworkName "${PROJECT_NAME}")
+
+add_subdirectory(task_2)
diff --git a/homework_6/task_2/CMakeLists.txt b/homework_6/task_2/CMakeLists.txt
new file mode 100644
index 0000000..42a5034
--- /dev/null
+++ b/homework_6/task_2/CMakeLists.txt
@@ -0,0 +1,9 @@
+project("${homeworkName}_task_2")
+
+add_library(cyclicList cyclicList.c)
+
+# add_executable(${PROJECT_NAME} main.c)
+# target_link_libraries(${PROJECT_NAME} cyclicList)
+
+add_executable(${PROJECT_NAME}_test test.c)
+target_link_libraries(${PROJECT_NAME}_test cyclicList)
diff --git a/homework_6/task_2/cyclicList.c b/homework_6/task_2/cyclicList.c
new file mode 100644
index 0000000..c0ce636
--- /dev/null
+++ b/homework_6/task_2/cyclicList.c
@@ -0,0 +1,52 @@
+#include "cyclicList.h"
+
+#include <stdlib.h>
+
+typedef struct ListElement {
+    struct ListElement *left;
+    struct ListElement *right;
+    int value;
+} ListElement;
+
+bool addElementAfter(ListElement *element, ListElement **newElement, int value) {
+    *newElement = malloc(sizeof(ListElement));
+    if (*newElement == NULL) {
+        return false;
+    }
+
+    if (element == NULL) {
+        (*newElement)->left = *newElement;
+        (*newElement)->right = *newElement;
+    } else {
+        (*newElement)->left = element;
+        (*newElement)->right = element->right;
+        element->right = *newElement;
+    }
+
+    (*newElement)->value = value;
+
+    return true;
+}
+
+ListElement *getNext(ListElement *element) {
+    return element->right;
+}
+
+int getValue(ListElement *element) {
+    return element->value;
+}
+
+void removeElement(ListElement *element) {
+    element->left->right = element->right;
+    element->right->left = element->left;
+    free(element);
+}
+
+void removeAllElements(ListElement *element) {
+    ListElement *right = element->right;
+    do {
+        ListElement *next = right->right;
+        removeElement(right);
+        right = next;
+    } while (right != element);
+}
diff --git a/homework_6/task_2/cyclicList.h b/homework_6/task_2/cyclicList.h
new file mode 100644
index 0000000..d0db94c
--- /dev/null
+++ b/homework_6/task_2/cyclicList.h
@@ -0,0 +1,30 @@
+#pragma once
+
+/// @brief Cyclic list element
+typedef struct ListElement ListElement;
+
+/// @brief Adds new element after specified element
+/// @param element Element that will be on the left relative to new element,
+/// must be `NULL` when creating new list
+/// @param newElement Pointer to store created `ListElement` to
+/// @param value Value to store in new element
+/// @return `true` if added successfully, `false` otherwise (allocaton failed)
+bool addElementAfter(ListElement *element, ListElement **newElement, int value);
+
+/// @brief Gets element on the right of the specified element
+/// @param element Element of cyclic list
+/// @return Element on the right of the specified element
+ListElement *getNext(ListElement *element);
+
+/// @brief Gets value of the specified element
+/// @param element Element of cyclic list
+/// @return Value of specified element
+int getValue(ListElement *element);
+
+/// @brief Removes an element (and calls `free()` on it)
+/// @param element Element to remove
+void removeElement(ListElement *element);
+
+/// @brief Removes all elements of cyclic list
+/// @param element Any element of the list
+void removeAllElements(ListElement *element);
diff --git a/homework_6/task_2/test.c b/homework_6/task_2/test.c
new file mode 100644
index 0000000..7753c20
--- /dev/null
+++ b/homework_6/task_2/test.c
@@ -0,0 +1,63 @@
+#define CTEST_MAIN
+#define CTEST_SEGFAULT
+#include "../../ctest/ctest.h"
+
+#include "cyclicList.h"
+
+int main(int argc, const char *argv[]) {
+    return ctest_main(argc, argv);
+}
+
+ListElement *add(ListElement *after, int value) {
+    ListElement *element;
+    ASSERT_TRUE(addElementAfter(after, &element, value));
+    ASSERT_NOT_NULL(element);
+
+    return element;
+}
+
+CTEST(cyclicListTests, createTest) {
+    ListElement *element = add(NULL, 0);
+
+    ASSERT_TRUE(getNext(element) == element);
+    ASSERT_TRUE(getNext(getNext(element)) == element);
+
+    removeAllElements(element);
+}
+
+CTEST(cyclicListTests, addElementTest) {
+    ListElement *elementA = add(NULL, 0);
+    ListElement *elementB = add(elementA, 1);
+    ListElement *elementC = add(elementB, 2);
+    ListElement *elementD = add(elementC, 3);
+
+    ASSERT_TRUE(getNext(elementA) == elementB);
+    ASSERT_TRUE(getNext(elementB) == elementC);
+    ASSERT_TRUE(getNext(elementC) == elementD);
+    ASSERT_TRUE(getNext(elementD) == elementA);
+
+    ASSERT_EQUAL(getValue(elementA), 0);
+    ASSERT_EQUAL(getValue(elementB), 1);
+    ASSERT_EQUAL(getValue(elementC), 2);
+    ASSERT_EQUAL(getValue(elementD), 3);
+
+    removeAllElements(elementA);
+}
+
+CTEST(cyclicListTests, removeElementTest) {
+    ListElement *elementA = add(NULL, 0);
+    ListElement *elementB = add(elementA, 0);
+    ListElement *elementC = add(elementB, 0);
+    ListElement *elementD = add(elementC, 0);
+
+    removeElement(elementB);
+    ASSERT_TRUE(getNext(elementA) == elementC);
+
+    removeElement(elementC);
+    ASSERT_TRUE(getNext(elementA) == elementD);
+
+    removeElement(elementD);
+    ASSERT_TRUE(getNext(elementA) == elementA);
+
+    removeAllElements(elementA);
+}

From bb8d7a302683098b2e10c6df3963ae2048d43c48 Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Thu, 31 Oct 2024 19:03:11 +0300
Subject: [PATCH 2/8] Refactored list (hw6 task 2)

---
 homework_6/task_2/cyclicList.c | 30 ++++++++++++++++++------------
 homework_6/task_2/cyclicList.h |  4 ++--
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/homework_6/task_2/cyclicList.c b/homework_6/task_2/cyclicList.c
index c0ce636..ab05b4e 100644
--- a/homework_6/task_2/cyclicList.c
+++ b/homework_6/task_2/cyclicList.c
@@ -8,22 +8,26 @@ typedef struct ListElement {
     int value;
 } ListElement;
 
-bool addElementAfter(ListElement *element, ListElement **newElement, int value) {
-    *newElement = malloc(sizeof(ListElement));
-    if (*newElement == NULL) {
+bool addElementAfter(ListElement *previous, ListElement **newElement, int value) {
+    ListElement *element = malloc(sizeof(ListElement));
+    if (element == NULL) {
         return false;
     }
 
-    if (element == NULL) {
-        (*newElement)->left = *newElement;
-        (*newElement)->right = *newElement;
+    if (previous == NULL) {
+        element->left = element;
+        element->right = element;
     } else {
-        (*newElement)->left = element;
-        (*newElement)->right = element->right;
-        element->right = *newElement;
+        ListElement *next = previous->right;
+        element->left = previous;
+        element->right = next;
+
+        next->left = element;
+        previous->right = element;
     }
 
-    (*newElement)->value = value;
+    element->value = value;
+    *newElement = element;
 
     return true;
 }
@@ -37,8 +41,10 @@ int getValue(ListElement *element) {
 }
 
 void removeElement(ListElement *element) {
-    element->left->right = element->right;
-    element->right->left = element->left;
+    ListElement *left = element->left;
+    ListElement *right = element->right;
+    left->right = right;
+    right->left = left;
     free(element);
 }
 
diff --git a/homework_6/task_2/cyclicList.h b/homework_6/task_2/cyclicList.h
index d0db94c..2202736 100644
--- a/homework_6/task_2/cyclicList.h
+++ b/homework_6/task_2/cyclicList.h
@@ -4,12 +4,12 @@
 typedef struct ListElement ListElement;
 
 /// @brief Adds new element after specified element
-/// @param element Element that will be on the left relative to new element,
+/// @param previous Element that will be on the left relative to new element,
 /// must be `NULL` when creating new list
 /// @param newElement Pointer to store created `ListElement` to
 /// @param value Value to store in new element
 /// @return `true` if added successfully, `false` otherwise (allocaton failed)
-bool addElementAfter(ListElement *element, ListElement **newElement, int value);
+bool addElementAfter(ListElement *previous, ListElement **newElement, int value);
 
 /// @brief Gets element on the right of the specified element
 /// @param element Element of cyclic list

From ee1b602e6bc87a76a2f0a8fb6f30e4f5627424ce Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Thu, 31 Oct 2024 19:04:15 +0300
Subject: [PATCH 3/8] Homework 6 task 2

---
 homework_6/task_2/CMakeLists.txt |  4 +--
 homework_6/task_2/main.c         | 54 ++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 homework_6/task_2/main.c

diff --git a/homework_6/task_2/CMakeLists.txt b/homework_6/task_2/CMakeLists.txt
index 42a5034..39ae0b1 100644
--- a/homework_6/task_2/CMakeLists.txt
+++ b/homework_6/task_2/CMakeLists.txt
@@ -2,8 +2,8 @@ project("${homeworkName}_task_2")
 
 add_library(cyclicList cyclicList.c)
 
-# add_executable(${PROJECT_NAME} main.c)
-# target_link_libraries(${PROJECT_NAME} cyclicList)
+add_executable(${PROJECT_NAME} main.c)
+target_link_libraries(${PROJECT_NAME} cyclicList)
 
 add_executable(${PROJECT_NAME}_test test.c)
 target_link_libraries(${PROJECT_NAME}_test cyclicList)
diff --git a/homework_6/task_2/main.c b/homework_6/task_2/main.c
new file mode 100644
index 0000000..44463de
--- /dev/null
+++ b/homework_6/task_2/main.c
@@ -0,0 +1,54 @@
+#include <stdio.h>
+
+#include "cyclicList.h"
+
+bool getLastWarrior(int warriorsCount, int killersPerWarrior, int *result) {
+    ListElement *lastElement = NULL;
+    for (int i = 0; i < warriorsCount; ++i) {
+        ListElement *newElement = NULL;
+        if (!addElementAfter(lastElement, &newElement, i + 1)) {
+            return false;
+        }
+
+        lastElement = newElement;
+    }
+
+    // set lastElement to point to element
+    lastElement = getNext(lastElement);
+
+    while (getNext(lastElement) != lastElement) {
+        for (int i = 0; i < killersPerWarrior; ++i) {
+            lastElement = getNext(lastElement);
+        }
+        ListElement *next = getNext(lastElement);
+        removeElement(lastElement);
+        lastElement = next;
+    }
+
+    *result = getValue(lastElement);
+    removeAllElements(lastElement);
+
+    return true;
+}
+
+int readValue(const char *prompt, const char *incorrectValueMessage) {
+    int value;
+    printf("%s", prompt);
+    while ((scanf("%d", &value) != 1) || value <= 0) {
+        while (getchar() != '\n') {}
+        printf("%s", incorrectValueMessage);
+    }
+}
+
+int main(void) {
+    int warriorsCount = readValue("warriors count: ", "incorrect value; warriors count should be greater than zero; try again: ");
+    int nthWarrior = readValue("n-th warrior to be killed: ", "incorrect value; n should be greater than zero; try again: ");
+
+    int result = 0;
+    if (!getLastWarrior(warriorsCount, nthWarrior - 1, &result)) {
+        printf("allocation error\n");
+        return 1;
+    }
+
+    printf("last warrior: %d\n", result);
+}

From 6470ad20359997b592a165896f1c1a33fb9754e7 Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Sat, 2 Nov 2024 17:35:29 +0300
Subject: [PATCH 4/8] Added missing return statement

---
 homework_6/task_2/main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/homework_6/task_2/main.c b/homework_6/task_2/main.c
index 44463de..1bd6edf 100644
--- a/homework_6/task_2/main.c
+++ b/homework_6/task_2/main.c
@@ -38,6 +38,7 @@ int readValue(const char *prompt, const char *incorrectValueMessage) {
         while (getchar() != '\n') {}
         printf("%s", incorrectValueMessage);
     }
+    return value;
 }
 
 int main(void) {

From 7e5f2d6e28a2dfad5f6bb09a132b7ea4352b091f Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Tue, 10 Dec 2024 03:21:48 +0300
Subject: [PATCH 5/8] Added stdbool.h includes (hw6 task 2)

---
 homework_6/task_2/cyclicList.c | 1 +
 homework_6/task_2/cyclicList.h | 2 ++
 homework_6/task_2/main.c       | 1 +
 3 files changed, 4 insertions(+)

diff --git a/homework_6/task_2/cyclicList.c b/homework_6/task_2/cyclicList.c
index ab05b4e..d5d7a96 100644
--- a/homework_6/task_2/cyclicList.c
+++ b/homework_6/task_2/cyclicList.c
@@ -1,5 +1,6 @@
 #include "cyclicList.h"
 
+#include <stdbool.h>
 #include <stdlib.h>
 
 typedef struct ListElement {
diff --git a/homework_6/task_2/cyclicList.h b/homework_6/task_2/cyclicList.h
index 2202736..bed6111 100644
--- a/homework_6/task_2/cyclicList.h
+++ b/homework_6/task_2/cyclicList.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <stdbool.h>
+
 /// @brief Cyclic list element
 typedef struct ListElement ListElement;
 
diff --git a/homework_6/task_2/main.c b/homework_6/task_2/main.c
index 1bd6edf..b2aa61b 100644
--- a/homework_6/task_2/main.c
+++ b/homework_6/task_2/main.c
@@ -1,3 +1,4 @@
+#include <stdbool.h>
 #include <stdio.h>
 
 #include "cyclicList.h"

From d226c392369cd382d70cba69b1192e8b4f5e0cf4 Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Tue, 10 Dec 2024 03:52:15 +0300
Subject: [PATCH 6/8] Added stdlib.h include (hw6 task 2)

---
 homework_6/task_2/test.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/homework_6/task_2/test.c b/homework_6/task_2/test.c
index 7753c20..6a22df2 100644
--- a/homework_6/task_2/test.c
+++ b/homework_6/task_2/test.c
@@ -2,6 +2,8 @@
 #define CTEST_SEGFAULT
 #include "../../ctest/ctest.h"
 
+#include <stdlib.h>
+
 #include "cyclicList.h"
 
 int main(int argc, const char *argv[]) {

From 45e8ccf9ce87bf16147ea4428a565e3d616ee346 Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Wed, 25 Dec 2024 19:30:23 +0300
Subject: [PATCH 7/8] Added task name to README (hw6 task 2)

---
 homework_6/README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/homework_6/README.md b/homework_6/README.md
index 4a2824e..3a5fddc 100644
--- a/homework_6/README.md
+++ b/homework_6/README.md
@@ -1 +1,3 @@
 # Homework 6
+
+[Task 1. Counting rhyme](/homework_6/task_2)

From 42a41660a8d2f4d1b136af96eaa47be3543542ce Mon Sep 17 00:00:00 2001
From: ilya-krivtsov <180809461+ilya-krivtsov@users.noreply.github.com>
Date: Wed, 25 Dec 2024 19:32:08 +0300
Subject: [PATCH 8/8] Fixed task name (hw6 task 2)

---
 homework_6/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/homework_6/README.md b/homework_6/README.md
index 3a5fddc..88e7b4d 100644
--- a/homework_6/README.md
+++ b/homework_6/README.md
@@ -1,3 +1,3 @@
 # Homework 6
 
-[Task 1. Counting rhyme](/homework_6/task_2)
+[Task 2. Counting rhyme](/homework_6/task_2)