From 926303a667b0876ceb5ab8bc5dcc0ab0828cb98f Mon Sep 17 00:00:00 2001
From: Pavel Kuliaka <pavel.kulyaka@yandex.ru>
Date: Sat, 15 Nov 2025 02:59:59 +0300
Subject: [PATCH] Implemented a rhyme solution using an array of cyclic lists

---
 Lists/cyclic_list_array.c | 138 ++++++++++++++++++++++++++++++++++++++
 Lists/cyclic_list_array.h |  34 ++++++++++
 Lists/rhyme.c             |  63 +++++++++++++++++
 3 files changed, 235 insertions(+)
 create mode 100644 Lists/cyclic_list_array.c
 create mode 100644 Lists/cyclic_list_array.h
 create mode 100644 Lists/rhyme.c

diff --git a/Lists/cyclic_list_array.c b/Lists/cyclic_list_array.c
new file mode 100644
index 0000000..e860fdf
--- /dev/null
+++ b/Lists/cyclic_list_array.c
@@ -0,0 +1,138 @@
+#include "cyclic_list_array.h"
+
+Status cyclicListArrayCreate(CyclicListArray **cyclicListArray)
+{
+    if (cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    *cyclicListArray = malloc(sizeof(CyclicListArray));
+    if (*cyclicListArray == NULL)
+    {
+        return MEMORY_ALLOCATION_ERROR;
+    }
+    (*cyclicListArray)->size = 0;
+    (*cyclicListArray)->position = 0;
+    (*cyclicListArray)->data = NULL;
+    return OK;
+}
+
+Status cyclicListArrayAdd(CyclicListArray *cyclicListArray, const int value)
+{
+    if (cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    int *data = malloc(sizeof(int) * (cyclicListArray->size + 1));
+    if (data == NULL)
+    {
+        return MEMORY_ALLOCATION_ERROR;
+    }
+    for (unsigned int index = 0; index < cyclicListArray->size; ++index)
+    {
+        data[index] = cyclicListArray->data[index];
+    }
+    data[cyclicListArray->size] = value;
+
+    free(cyclicListArray->data);
+    cyclicListArray->data = data;
+    cyclicListArray->size++;
+
+    return OK;
+}
+
+Status cyclicListArrayNext(CyclicListArray *cyclicListArray)
+{
+    if (cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    if (cyclicListArray->size == 0)
+    {
+        return EMPTY_LIST;
+    }
+    cyclicListArray->position = (cyclicListArray->position + 1) % cyclicListArray->size;
+    return OK;
+}
+
+Status cyclicListArrayPrevious(CyclicListArray *cyclicListArray)
+{
+    if (cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    if (cyclicListArray->size == 0)
+    {
+        return EMPTY_LIST;
+    }
+    cyclicListArray->position = (cyclicListArray->position - 1 + cyclicListArray->size) % cyclicListArray->size;
+    return OK;
+}
+
+Status cyclicListArrayGetCurrent(const CyclicListArray *cyclicListArray, int *address)
+{
+    if (cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    if (cyclicListArray->size == 0)
+    {
+        return EMPTY_LIST;
+    }
+    *address = cyclicListArray->data[cyclicListArray->position];
+    return OK;
+}
+
+Status cyclicListArrayRemoveCurrent(CyclicListArray *cyclicListArray)
+{
+    if (cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    if (cyclicListArray->size == 0)
+    {
+        return EMPTY_LIST;
+    }
+
+    int *data = malloc(sizeof(int) * (cyclicListArray->size - 1));
+    if (data == NULL)
+    {
+        return MEMORY_ALLOCATION_ERROR;
+    }
+    int offset = 0;
+    for (unsigned int index = 0; index < cyclicListArray->size; ++index)
+    {
+        if (offset == 0 && index == cyclicListArray->position)
+        {
+            offset = 1;
+        }
+        else
+        {
+            data[index - offset] = cyclicListArray->data[index];
+        }
+    }
+    free(cyclicListArray->data);
+    cyclicListArray->data = data;
+    cyclicListArray->size--;
+    if (cyclicListArray->size > 0)
+    {
+        cyclicListArray->position = cyclicListArray->position % cyclicListArray->size;
+    }
+    else
+    {
+        cyclicListArray->position = 0;
+    }
+    return OK;
+}
+
+Status cyclicListArrayFree(CyclicListArray **cyclicListArray)
+{
+    if (cyclicListArray == NULL || *cyclicListArray == NULL)
+    {
+        return NULL_POINTER_ARGUMENT_ERROR;
+    }
+    free((*cyclicListArray)->data);
+    free(*cyclicListArray);
+    *cyclicListArray = NULL;
+    return OK;
+}
diff --git a/Lists/cyclic_list_array.h b/Lists/cyclic_list_array.h
new file mode 100644
index 0000000..9ed5c08
--- /dev/null
+++ b/Lists/cyclic_list_array.h
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef enum StatusesEnum
+{
+    OK,
+    MEMORY_ALLOCATION_ERROR,
+    NULL_POINTER_ARGUMENT_ERROR,
+    EMPTY_LIST,
+    NOT_INCLUDE_VALUE
+} Status;
+
+typedef struct CyclicListArrayStruct
+{
+    int *data;
+    int size;
+    unsigned int position;
+} CyclicListArray;
+
+Status cyclicListArrayCreate(CyclicListArray **cyclicListArray);
+
+Status cyclicListArrayAdd(CyclicListArray *cyclicListArray, const int value);
+
+Status cyclicListArrayNext(CyclicListArray *cyclicListArray);
+
+Status cyclicListArrayPrevious(CyclicListArray *cyclicListArray);
+
+Status cyclicListArrayGetCurrent(const CyclicListArray *cyclicListArray, int *address);
+
+Status cyclicListArrayRemoveCurrent(CyclicListArray *cyclicListArray);
+
+Status cyclicListArrayFree(CyclicListArray **cyclicListArray);
diff --git a/Lists/rhyme.c b/Lists/rhyme.c
new file mode 100644
index 0000000..6dbf944
--- /dev/null
+++ b/Lists/rhyme.c
@@ -0,0 +1,63 @@
+#include "cyclic_list_array.h"
+
+int main(void)
+{
+    const int n = 4;
+    const int m = 7;
+
+    CyclicListArray *cyclicListArray;
+    Status status = cyclicListArrayCreate(&cyclicListArray);
+    if (status != OK)
+    {
+        puts("Error creating list");
+        return 1;
+    }
+    for (unsigned int number = 1; number <= n; ++number)
+    {
+        status = cyclicListArrayAdd(cyclicListArray, (int)number);
+        if (status != OK)
+        {
+            puts("Error adding element");
+            cyclicListArrayFree(&cyclicListArray);
+            return 1;
+        }
+    }
+
+    while (cyclicListArray->size > 1)
+    {
+        const unsigned int remove_index =
+            (cyclicListArray->position + (unsigned int)(m - 1)) % (unsigned int)cyclicListArray->size;
+
+        while (cyclicListArray->position != remove_index)
+        {
+            status = cyclicListArrayNext(cyclicListArray);
+            if (status != OK)
+            {
+                puts("Error moving to next");
+                cyclicListArrayFree(&cyclicListArray);
+                return 1;
+            }
+        }
+
+        status = cyclicListArrayRemoveCurrent(cyclicListArray);
+        if (status != OK)
+        {
+            puts("Error removing element");
+            cyclicListArrayFree(&cyclicListArray);
+            return 1;
+        }
+    }
+
+    int result;
+    status = cyclicListArrayGetCurrent(cyclicListArray, &result);
+    if (status != OK)
+    {
+        puts("Error getting result");
+        cyclicListArrayFree(&cyclicListArray);
+        return 1;
+    }
+
+    cyclicListArrayFree(&cyclicListArray);
+    printf("%d", result);
+    return 0;
+}