117 lines
2.7 KiB
C
117 lines
2.7 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#define HASH_TABLE_SIZE 32
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// NOTE: the data is some value, which is on a certain 2D point (x,y)
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typedef struct node
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{
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// the data
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int x,y;
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float Value;
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// next entrie in the hashtable, if there were a collision
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struct node *Next;
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}node;
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#include "linked_list.h"
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/*
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* Linked-list interface
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*
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* void list_add(node **Head, int Value, int x, int y);
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*
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* node *list_get(node **Head, int x, int y);
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*
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* void list_remove(node **Head, node *Node);
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*
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*/
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int hash(int x, int y)
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{
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int Result = (x + y)%HASH_TABLE_SIZE;
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if(Result < 0)
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Result *= -1;
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return Result;
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}
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void hash_add(node **HashTable, float Value, int x, int y)
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{
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int Hash = hash(x,y);
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node *Head = HashTable[Hash];
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list_add(&Head, Value, x, y);
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// Don't forget to update the Hashtables pointer to the head.
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HashTable[Hash] = Head;
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}
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node *hash_get(node **HashTable, int x, int y)
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{
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int Hash = hash(x,y);
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node *Head = HashTable[Hash];
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node *Result = list_get(&Head, x, y);
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return Result;
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}
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void hash_remove(node **HashTable, int x, int y)
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{
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int Hash = hash(x,y);
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node *Head = HashTable[Hash];
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node *Node = list_get(&Head, x, y);
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if(Node)
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list_remove(&Head, Node);
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}
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int main(int argc, char *argv)
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{
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node *HashTable[HASH_TABLE_SIZE] = {};
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//payload D1 = {0, 0, 1.0, 0};
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hash_add(HashTable, 1.0, 1, 0);
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hash_add(HashTable, 3.0, 0, 1);
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hash_add(HashTable, 5.0, 3, -2);
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hash_add(HashTable, 7.0, 10, 3);
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// Note: Test adding with collisions
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node *Node = hash_get(HashTable, 1, 0);
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if(Node)
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printf("Succesfully added value %f at position (%d,%d) to the HashTable\n", Node->Value, Node->x, Node->y);
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else
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printf("Failed to add or find value 1 at position (1,0)\n");
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Node = hash_get(HashTable, 0, 1);
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int added01 = 0;
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if(Node)
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{
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printf("Succesfully added value %f at position (%d,%d) to the HashTable\n", Node->Value, Node->x, Node->y);
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added01 = 1;
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}
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else
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printf("Failed to add or find value 3 at position (0,1)\n");
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Node = hash_get(HashTable, 3, -2);
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if(Node)
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printf("Succesfully added value %f at position (%d,%d) to the HashTable\n", Node->Value, Node->x, Node->y);
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else
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printf("Failed to add or find value 5 at position (-2,-2)\n");
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Node = hash_get(HashTable, 10, 3);
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if(Node)
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printf("Succesfully added value %f at position (%d,%d) to the HashTable\n", Node->Value, Node->x, Node->y);
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else
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printf("Failed to add or find value 7 at position (10,3)\n");
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// NOTE: Test removing element
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if(added01)
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{
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hash_remove(HashTable, 0, 1);
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Node = hash_get(HashTable, 0, 1);
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if(!Node)
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printf("Succesfully removed entrie at position (0,1) from the HashTable\n");
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else
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printf("Failed to remove entrie at position (0,1)\n");
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}
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}
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