Homework 6 - Task 3 - [Sorted list]

homework_6/CMakeLists.txt

@@ -3,3 +3,4 @@ project(homework_6)
 set(homeworkName "${PROJECT_NAME}")
 
 add_subdirectory(task_1)
+add_subdirectory(task_3)

homework_6/README.md

@@ -1,3 +1,5 @@
 # Homework 6
 
 [Task 1. Merge sort](/homework_6/task_1)
+
+[Task 3. Sorted list](/homework_6/task_3)

homework_6/task_3/CMakeLists.txt

@@ -0,0 +1,9 @@
+project("${homeworkName}_task_3")
+
+add_library(sortedList sortedList.c)
+
+add_executable(${PROJECT_NAME} main.c)
+target_link_libraries(${PROJECT_NAME} sortedList)
+
+add_executable(${PROJECT_NAME}_test test.c)
+target_link_libraries(${PROJECT_NAME}_test sortedList)

homework_6/task_3/main.c

@@ -0,0 +1,134 @@
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "sortedList.h"
+
+typedef enum {
+    Exit,
+    Menu,
+    AddElement,
+    RemoveElement,
+    PrintList
+} State;
+
+State readCommand(void) {
+    int command = -1;
+    if (scanf("%d", &command) != 1) {
+        command = -1;
+    }
+    while (getchar() != '\n') {}
+    switch (command) {
+    case 0:
+        return Exit;
+    case 1:
+        return AddElement;
+    case 2:
+        return RemoveElement;
+    case 3:
+        return PrintList;
+    default:
+        printf("Error: unknown command\n");
+        return Menu;
+    }
+}
+
+State addElementCommand(SortedList *list) {
+    printf("Enter a number to add: ");
+    int value = 0;
+    if (scanf("%d", &value) != 1) {
+        printf("Error: not a number\n");
+        return Menu;
+    }
+
+    if (!addElement(list, value)) {
+        printf("Error: cannot add number\n");
+        return Menu;
+    }
+
+    return Menu;
+}
+
+State removeElementCommand(SortedList *list) {
+    printf("Enter a number to remove: ");
+    int value = 0;
+    if (scanf("%d", &value) != 1) {
+        printf("Error: not a number\n");
+        return Menu;
+    }
+
+    if (!removeElement(list, value)) {
+        printf("Error: cannot remove number; probably, it isn't in the list\n");
+        return Menu;
+    }
+
+    return Menu;
+}
+
+State printListCommand(SortedList *list) {
+    printf("[ ");
+    Element *element = getFirst(list);
+    while (element != NULL) {
+        printf("%d", getValue(element));
+
+        element = getNext(element);
+        if (element != NULL) {
+            printf(", ");
+        }
+    }
+    printf(" ]\n");
+
+    return Menu;
+}
+
+bool doConversation(SortedList *list) {
+    printf("Sorted list\n");
+    printf("Available commands: \n");
+    printf("  0 - exit;\n");
+    printf("  1 - add a number;\n");
+    printf("  2 - remove a number;\n");
+    printf("  3 - print list.\n");
+
+    State state = Menu;
+    while (true) {
+        switch (state)
+        {
+        case Exit:
+            return true;
+
+        case Menu:
+            printf("sorted_list> ");
+            state = readCommand();
+            break;
+
+        case AddElement:
+            state = addElementCommand(list);
+            break;
+
+        case RemoveElement:
+            state = removeElementCommand(list);
+            break;
+
+        case PrintList:
+            state = printListCommand(list);
+            break;
+
+        default:
+            printf("Error: unknown state\n");
+            return false;
+        }
+    }
+}
+
+int main(void) {
+    SortedList *list = NULL;
+    if (!createList(&list)) {
+        printf("Error: allocation failed\n");
+        return 1;
+    }
+
+    if (!doConversation(list)) {
+        disposeList(list);
+        return 1;
+    }
+    disposeList(list);
+}

homework_6/task_3/sortedList.c

@@ -0,0 +1,118 @@
+#include "sortedList.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+typedef struct Element {
+    int value;
+    struct Element *next;
+} Element;
+
+typedef struct SortedList {
+    Element *first;
+} SortedList;
+
+bool createList(SortedList **list) {
+    *list = malloc(sizeof(SortedList));
+    if (*list == NULL) {
+        return false;
+    }
+
+    (*list)->first = NULL;
+    // (*list)->last = NULL;
+
+    return true;
+}
+
+bool addElement(SortedList *list, int value) {
+    Element *element = malloc(sizeof(Element));
+    if (element == NULL) {
+        return false;
+    }
+
+    element->value = value;
+    element->next = NULL;
+
+    if (list->first == NULL) {
+        list->first = element;
+        return true;
+    }
+
+    if (value < getValue(list->first)) {
+        element->next = list->first;
+        list->first = element;
+        return true;
+    }
+
+    Element *last = list->first;
+    while (last->next != NULL) {
+        if (getValue(last->next) > value) {
+            break;
+        }
+
+        last = last->next;
+    }
+
+    element->next = last->next;
+    last->next = element;
+
+    return true;
+}
+
+bool removeElement(SortedList *list, int value) {
+    if (list->first == NULL) {
+        return false;
+    }
+
+    if (value < getValue(list->first)) {
+        return false;
+    }
+
+    if (value == getValue(list->first)) {
+        Element *next = list->first->next;
+        free(list->first);
+        list->first = next;
+        return true;
+    }
+
+    Element *last = list->first;
+    while (last->next != NULL) {
+        if (getValue(last->next) == value) {
+            break;
+        }
+
+        last = last->next;
+    }
+
+    if (last->next == NULL) {
+        return false;
+    }
+
+    Element *next = last->next->next;
+    free(last->next);
+    last->next = next;
+
+    return true;
+}
+
+Element *getFirst(SortedList *list) {
+    return list->first;
+}
+
+void disposeList(SortedList *list) {
+    Element *last = list->first;
+    while (last != NULL) {
+        Element *next = last->next;
+        free(last);
+        last = next;
+    }
+    free(list);
+}
+
+Element *getNext(Element *element) {
+    return element->next;
+}
+
+int getValue(Element *element) {
+    return element->value;
+}

homework_6/task_3/sortedList.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <stdbool.h>
+
+/// @brief Element of the sorted list
+typedef struct Element Element;
+
+/// @brief List of numbers that remains always sorted
+typedef struct SortedList SortedList;
+
+/// @brief Creates new instance of `SortedList`
+/// @param list Pointer to store list to
+/// @return `true` if created successfully, `false` otherwise (allocation failed)
+bool createList(SortedList **list);
+
+/// @brief Adds value to list
+/// @param list List to add value to
+/// @param value Value to add
+/// @return `true` if added successfully, `false` otherwise (allocation failed)
+bool addElement(SortedList *list, int value);
+
+/// @brief Removes value from list
+/// @param list List to remove value from
+/// @param value Value to remove
+/// @return `true` if removed successfully, `false` otherwise (element doesn't exist in list)
+bool removeElement(SortedList *list, int value);
+
+/// @brief Gets first element in list
+/// @param list List to get first element from
+/// @return First element in list
+Element *getFirst(SortedList *list);
+
+/// @brief Disposes list and all of its elements
+/// @param list List to dispose
+void disposeList(SortedList *list);
+
+/// @brief Gets element that follows specified element
+/// @param element An element
+/// @return Element that follows specified element
+Element *getNext(Element *element);
+
+/// @brief Gets value of specified element
+/// @param element An element
+/// @return Value of an element
+int getValue(Element *element);