mirror of
https://github.com/TheAlgorithms/C
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124 lines
2.9 KiB
C
124 lines
2.9 KiB
C
/**
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* @file
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* @brief Program to generate [Cantor ternary
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* set](https://en.wikipedia.org/wiki/Cantor_set)
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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/** structure to define Cantor set */
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typedef struct _cantor_set
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{
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double start; /**< start of interval */
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double end; /**< end of interval */
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struct _cantor_set *next; /**< pointer to next set */
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} CantorSet;
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/** Iterative constructor of all sets in the current level. This function
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* dynamically allocates memory when creating new sets. These are freed by the
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* function ::free_memory.
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* @param head pointer to interval set instance to update
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*/
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void propagate(CantorSet *head)
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{
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// if input is NULL, ignore the process
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if (head == NULL)
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return;
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CantorSet *temp = head; // local pointer to track propagation
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// create new node for the new set
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CantorSet *newNode = (CantorSet *)malloc(sizeof(CantorSet));
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// get 1/3rd of interval
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double diff = (((temp->end) - (temp->start)) / 3);
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// update interval ranges
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newNode->end = temp->end;
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temp->end = ((temp->start) + diff);
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newNode->start = (newNode->end) - diff;
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// update pointer to next set in this level
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newNode->next = temp->next;
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// point to next set
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temp->next = newNode;
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// create next set
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propagate(temp->next->next);
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}
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/** Print sets in the current range to `stdout`
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* @param head pointer to first set in the current level
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*/
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void print(CantorSet *head)
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{
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CantorSet *temp = head;
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while (temp != NULL) // print while a valid set is found
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{
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printf("\t");
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printf("[%lf] -- ", temp->start);
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printf("[%lf]", temp->end);
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temp = temp->next;
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}
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printf("\n");
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}
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/** Clear memory allocated by ::propagate function.
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* @param head pointer to first allocated instance.
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*/
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void free_memory(CantorSet *head)
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{
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if (!head)
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return;
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if (head->next)
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free_memory(head->next);
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free(head);
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}
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/** Main function */
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int main(int argc, char const *argv[])
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{
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int start_num, end_num, levels;
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if (argc < 2)
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{
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printf("Enter 3 arguments: start_num \t end_num \t levels\n");
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scanf("%d %d %d", &start_num, &end_num, &levels);
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}
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else
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{
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start_num = atoi(argv[1]);
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end_num = atoi(argv[2]);
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levels = atoi(argv[3]);
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}
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if (start_num < 0 || end_num < 0 || levels < 0)
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{
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fprintf(stderr, "All numbers must be positive\n");
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return -1;
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}
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CantorSet head = {.start = start_num, .end = end_num, .next = NULL};
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// loop to propagate each level from top to bottom
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for (int i = 0; i < levels; i++)
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{
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printf("Level %d\t", i);
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print(&head);
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propagate(&head);
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printf("\n");
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}
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printf("Level %d\t", levels);
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print(&head);
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// delete all memory allocated
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free_memory(head.next);
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return 0;
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}
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