formatting source-code for 153fb7b8a5

hashing/double_hash_hash_table.cpp

@@ -25,55 +25,44 @@ int size;
 bool rehashing;
 
 // Node that holds key
-struct Entry
-{
+struct Entry {
     explicit Entry(int key = notPresent) : key(key) {}
     int key;
 };
 
 // Hash a key
-int hashFxn(int key)
-{
+int hashFxn(int key) {
     std::hash<int> hash;
     return hash(key);
 }
 
 // Used for second hash function
-int otherHashFxn(int key)
-{
+int otherHashFxn(int key) {
     std::hash<int> hash;
     return 1 + (7 - (hash(key) % 7));
 }
 
 // Performs double hashing to resolve collisions
-int doubleHash(int key, bool searching)
-{
+int doubleHash(int key, bool searching) {
     int hash = static_cast<int>(fabs(hashFxn(key)));
     int i = 0;
     Entry entry;
-    do
-    {
+    do {
         int index = static_cast<int>(fabs((hash + (i * otherHashFxn(key))))) %
                     totalSize;
         entry = table[index];
-        if (searching)
-        {
-            if (entry.key == notPresent)
-            {
+        if (searching) {
+            if (entry.key == notPresent) {
                 return notPresent;
             }
-            if (searchingProber(entry, key))
-            {
+            if (searchingProber(entry, key)) {
                 cout << "Found key!" << endl;
                 return index;
             }
             cout << "Found tombstone or equal hash, checking next" << endl;
             i++;
-        }
-        else
-        {
-            if (putProber(entry, key))
-            {
+        } else {
+            if (putProber(entry, key)) {
                 if (!rehashing)
                     cout << "Spot found!" << endl;
                 return index;
@@ -87,8 +76,7 @@ int doubleHash(int key, bool searching)
                      << ")" << endl;
             i++;
         }
-        if (i == totalSize * 100)
-        {
+        if (i == totalSize * 100) {
             cout << "DoubleHash probe failed" << endl;
             return notPresent;
         }
@@ -97,38 +85,28 @@ int doubleHash(int key, bool searching)
 }
 
 // Finds empty spot
-bool putProber(Entry entry, int key)
-{
-    if (entry.key == notPresent || entry.key == tomb)
-    {
+bool putProber(Entry entry, int key) {
+    if (entry.key == notPresent || entry.key == tomb) {
         return true;
     }
     return false;
 }
 
 // Looks for a matching key
-bool searchingProber(Entry entry, int key)
-{
+bool searchingProber(Entry entry, int key) {
     if (entry.key == key)
         return true;
     return false;
 }
 
 // Displays the table
-void display()
-{
-    for (int i = 0; i < totalSize; i++)
-    {
-        if (table[i].key == notPresent)
-        {
+void display() {
+    for (int i = 0; i < totalSize; i++) {
+        if (table[i].key == notPresent) {
             cout << " Empty ";
-        }
-        else if (table[i].key == tomb)
-        {
+        } else if (table[i].key == tomb) {
             cout << " Tomb ";
-        }
-        else
-        {
+        } else {
             cout << " ";
             cout << table[i].key;
             cout << " ";
@@ -138,8 +116,7 @@ void display()
 }
 
 // Rehashes the table into a bigger table
-void rehash()
-{
+void rehash() {
     // Necessary so wall of add info isn't printed all at once
     rehashing = true;
     int oldSize = totalSize;
@@ -147,10 +124,8 @@ void rehash()
     // Really this should use the next prime number greater than totalSize * 2
     table = new Entry[totalSize * 2];
     totalSize *= 2;
-    for (int i = 0; i < oldSize; i++)
-    {
-        if (oldTable[i].key != -1 && oldTable[i].key != notPresent)
-        {
+    for (int i = 0; i < oldSize; i++) {
+        if (oldTable[i].key != -1 && oldTable[i].key != notPresent) {
             size--;  // Size stays the same (add increments size)
             add(oldTable[i].key);
         }
@@ -161,25 +136,21 @@ void rehash()
 }
 
 // Checks for load factor here
-void add(int key)
-{
+void add(int key) {
     Entry* entry = new Entry();
     entry->key = key;
     int index = doubleHash(key, false);
     table[index] = *entry;
     // Load factor greater than 0.5 causes resizing
-    if (++size / static_cast<double>(totalSize) >= 0.5)
-    {
+    if (++size / static_cast<double>(totalSize) >= 0.5) {
         rehash();
     }
 }
 
 // Removes key. Leaves tombstone upon removal.
-void remove(int key)
-{
+void remove(int key) {
     int index = doubleHash(key, true);
-    if (index == notPresent)
-    {
+    if (index == notPresent) {
         cout << "key not found" << endl;
     }
     table[index].key = tomb;
@@ -188,8 +159,7 @@ void remove(int key)
 }
 
 // Information about the adding process
-void addInfo(int key)
-{
+void addInfo(int key) {
     cout << "Initial table: ";
     display();
     cout << endl;
@@ -202,8 +172,7 @@ void addInfo(int key)
 }
 
 // Information about removal process
-void removalInfo(int key)
-{
+void removalInfo(int key) {
     cout << "Initial table: ";
     display();
     cout << endl;
@@ -216,15 +185,13 @@ void removalInfo(int key)
 }
 
 // I/O
-int main(void)
-{
+int main(void) {
     int cmd, hash, key;
     cout << "Enter the initial size of Hash Table. = ";
     cin >> totalSize;
     table = new Entry[totalSize];
     bool loop = true;
-    while (loop)
-    {
+    while (loop) {
         system("pause");
         cout << endl;
         cout << "PLEASE CHOOSE -" << endl;
@@ -235,8 +202,7 @@ int main(void)
         cout << "5. Display Hash table." << endl;
         cout << "6. Exit." << endl;
         cin >> cmd;
-        switch (cmd)
-        {
+        switch (cmd) {
         case 1:
             cout << "Enter key to add = ";
             cin >> key;
@@ -247,13 +213,11 @@ int main(void)
             cin >> key;
             removalInfo(key);
             break;
-        case 3:
-        {
+        case 3: {
             cout << "Enter key to search = ";
             cin >> key;
             Entry entry = table[doubleHash(key, true)];
-            if (entry.key == notPresent)
-            {
+            if (entry.key == notPresent) {
                 cout << "Key not present";
             }
             break;