hash_search

search/hash_search.cpp

@@ -1,11 +1,15 @@
 // Copyright 2020 Arctic2333
 #include <stdlib.h>
 #include<stdio.h>
-#define MAX 6
-# define HASHMAX 5
-// Hash Search Algorithm
-// Best Time Complexity Ω(1)
-int data[MAX] = { 12, 160, 219, 522, 725, 9997};
+#define MAX 6  // Determines how much data
+# define HASHMAX 5  // Determines the length of the hash table 
+/**
+  * Hash Search Algorithm
+  * Best Time Complexity Ω(1)
+  * In this algorithm, we use the method of division and reservation remainder to construct the hash function, 
+  * and use the method of chain address to solve the conflict, that is, we link a chain list after the data, 
+  * and store all the records whose keywords are synonyms in the same linear chain list. */
+int data[MAX] = { 1, 10, 15, 5, 8, 7};  // test data
 typedef struct list {
     int key;
     struct list * next;
@@ -13,12 +17,16 @@ typedef struct list {
 node, * link;
 node hashtab[HASHMAX];
 int counter = 1;
+/* int h(int key)
+ * Mode of hash detection :
+ * Division method */
 int h(int key) {
     return key % HASHMAX;
 }
-/* In this algorithm, we use the method of division and reservation remainder to construct the hash function, 
-   and use the method of chain address to solve the conflict, that is, we link a chain list after the data, 
-   and store all the records whose keywords are synonyms in the same linear chain list. */
+/* void create_list(int key)
+ * The same after the remainder will be added after the same hash header
+ * To avoid conflict, zipper method is used
+ * Insert elements into the linked list in the header */
 void create_list(int key) {  // Construct hash table
     link p, n;
     int index;
@@ -33,6 +41,11 @@ void create_list(int key) {  // Construct hash table
     } else {
         hashtab[index].next = n; }
 }
+/* int hash_search(int key)
+ * Input the key to be searched, and get the hash header position through the H (int key) function,
+ * then one-dimensional linear search.
+ * If found @return element depth and number of searches
+ * If not found @return -1 */
 int hash_search(int key) {  // Hash lookup function
     link pointer;
     int index;
@@ -42,7 +55,7 @@ int hash_search(int key) {  // Hash lookup function
     printf("data[%d]:", index);
     while (pointer != NULL) {
         counter++;
-        printf("data[%d]:", pointer -> next);
+        printf("data[%d]:", pointer -> key);
         if (pointer -> key == key)
             return 1;
         else
@@ -52,19 +65,16 @@ int hash_search(int key) {  // Hash lookup function
 }
 int main() {
     link p;
-    int key, index, i;
+    int key, index, i;  // Key is the value to be found
     index = 0;
-    printf("input data:");
-    for (i = 0; i < HASHMAX; i++)
-        scanf("%d", & data[i]);
-    printf("\n");
+    // You can write the input mode here
     while (index < MAX) {  // Construct hash table
         create_list(data[index]);
         index++;
     }
     for (i = 0; i < HASHMAX; i++) {  // Output hash table
         printf("hashtab [%d]", i);
-        printf("n");
+        printf("\n");
         p = hashtab[i].next;
         while (p != NULL) {
             printf("please int key:");
@@ -75,12 +85,16 @@ int main() {
         printf("\n");
     }
     while (key != -1) {
-        printf("please input data\n");
-        scanf("%d", & key);
+        // You can write the input mode here
+        // test key = 10
+        key = 10;
         if (hash_search(key))
             printf("search time = %d\n", counter);
         else
             printf("no found!\n");
+        key = -1;  // Exit test
+        /* The test sample is returned as: data[0]:data[5]:data[15]:data[10]:search time = 3
+         * The search is successful. There are 10 in this set of data */
     }
     return 0;
 }