101 lines
2.1 KiB
C
101 lines
2.1 KiB
C
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/* License: AGPLv3 or later. https://www.gnu.org/licenses/licenses.html
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*
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* Exercise 5 - Hash Map (Week 6)
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* Name: Manish
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* Student Login: *****
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*
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* Compile as:
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* $ gcc -std=c11 -Wall -o ex5 ex5.c
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*/
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#include <stdio.h>
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#include <stdlib.h>
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typedef struct entry
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{
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int data;
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struct entry * next;
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} entry;
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/* This method of array initialization is GNU C extension and
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* may not work with other compilers. Not even g++
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*/
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entry hashmap[100] = {[0 ... 99] = (entry){.data = -1, .next = NULL}};
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int size = 0;
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int abs(int i);
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int main(void)
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{
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printf("Enter file name: ");
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char filename[257];
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// Assuming filename/file path won't be longer than 256 characters
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scanf("%256s", filename);
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FILE* file = fopen(filename, "r");
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if (!file)
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{
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perror(filename);
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exit(EXIT_FAILURE);
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}
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int num;
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int key;
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entry * node;
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while (fscanf(file, "%d", &num) != EOF)
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{
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key = abs(num%100);
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if (hashmap[key].data == -1) // empty
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hashmap[key].data = num;
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else // chaining
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{
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node = &hashmap[key];
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while (node->next != NULL)
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{
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node = node->next;
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}
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entry * new_entry = malloc(sizeof(entry));
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new_entry->data = num;
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new_entry->next = NULL;
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node->next = new_entry;
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}
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}
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int empty = 0;
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for (int i=0; i < 100; i++)
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{
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if (hashmap[i].data == -1)
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empty++;
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}
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int max_chain = 0;
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int current_chain = 0;
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for (int i=0; i < 100; i++)
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{
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if (hashmap[i].data == -1) // if empty, chain is 0
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continue;
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current_chain = 1; // if not empty, chain is at least 1 long
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node = hashmap[i].next;
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while (node != NULL)
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{
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current_chain++;
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node = node->next;
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}
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if (current_chain > max_chain)
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max_chain = current_chain;
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}
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printf("Empty Entries: %d\nLongest Chain: %d\n", empty, max_chain);
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fclose(file);
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return 0;
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}
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int abs(int i)
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{
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if (i < 0)
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return -i;
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return i;
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}
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