Merge pull request #3 from shadowcodex/dev-01

Dev 01

benchmark/stacks.js

@@ -1,34 +1,196 @@
 let { stacks } = require('./../index');
 let ptime = require('quick-ptime');
+const Table = require('cli-table');
 
 
 // setup stacks
-let stack = new stacks.Stack();
-let arrayStack = new stacks.ArrayStack();
+let linkedStack = new stacks.LinkedStack();
+let uArrayStack = new stacks.UArrayStack();
+let bArrayStack = new stacks.BArrayStack(1100001);
+
+/**
+ * PUSH STUFF
+ */
 
 // push 100,000 items onto the stack
 ptime.setTime('stack100000');
 for(let i = 0; i < 100000; i++) {
-    stack.push('value');
+    linkedStack.push('value');
+}
+let stackTime = ptime.elapsedTime('stack100000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1,000,000 items onto the stack
+ptime.setTime('stack1000000');
+for(let i = 0; i < 1000000; i++) {
+    linkedStack.push('value');
+}
+let mStackTime = ptime.elapsedTime('stack1000000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1 item onto the stack
+ptime.setTime('stack1');
+for(let i = 0; i < 1; i++) {
+    linkedStack.push('value');
 }
-console.log("Push 100,000 Stack timing:", ptime.elapsedTime('stack100000').formatted);
+let sStackTime = ptime.elapsedTime('stack1');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+
+
 
-ptime.setTime('arraystack100000');
+
+// push 100,000 items onto the stack
+ptime.setTime('ustack100000');
 for(let i = 0; i < 100000; i++) {
-    arrayStack.push('value');
+    uArrayStack.push('value');
+}
+let ustackTime = ptime.elapsedTime('ustack100000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1,000,000 items onto the stack
+ptime.setTime('ustack1000000');
+for(let i = 0; i < 1000000; i++) {
+    uArrayStack.push('value');
 }
-console.log("Push 100,000 Array Stack timing:", ptime.elapsedTime('arraystack100000').formatted);
+let umStackTime = ptime.elapsedTime('ustack1000000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1 item onto the stack
+ptime.setTime('ustack1');
+for(let i = 0; i < 1; i++) {
+    uArrayStack.push('value');
+}
+let usStackTime = ptime.elapsedTime('ustack1');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
 
 
-// pop 100,000 items off the stack
+
+// push 100,000 items onto the stack
+ptime.setTime('bstack100000');
+for(let i = 0; i < 100000; i++) {
+    bArrayStack.push('value');
+}
+let bstackTime = ptime.elapsedTime('bstack100000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1,000,000 items onto the stack
+ptime.setTime('bstack1000000');
+for(let i = 0; i < 1000000; i++) {
+    bArrayStack.push('value');
+}
+let bmStackTime = ptime.elapsedTime('bstack1000000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1 item onto the stack
+ptime.setTime('bstack1');
+for(let i = 0; i < 1; i++) {
+    bArrayStack.push('value');
+}
+let bsStackTime = ptime.elapsedTime('bstack1');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+
+
+
+/**
+ * POP STUFF
+ */
+
+// push 100,000 items onto the stack
 ptime.setTime('pstack100000');
 for(let i = 0; i < 100000; i++) {
-    stack.pop()
+    linkedStack.pop('value');
 }
-console.log("Pop 100,000 Stack timing:", ptime.elapsedTime('pstack100000').formatted);
+let pstackTime = ptime.elapsedTime('pstack100000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
 
-ptime.setTime('parraystack100000');
+// push 1,000,000 items onto the stack
+ptime.setTime('pstack1000000');
+for(let i = 0; i < 1000000; i++) {
+    linkedStack.pop('value');
+}
+let pmStackTime = ptime.elapsedTime('pstack1000000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1 item onto the stack
+ptime.setTime('pstack1');
+for(let i = 0; i < 1; i++) {
+    linkedStack.pop('value');
+}
+let psStackTime = ptime.elapsedTime('pstack1');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+
+
+// push 100,000 items onto the stack
+ptime.setTime('upstack100000');
 for(let i = 0; i < 100000; i++) {
-    stack.pop()
+    uArrayStack.pop('value');
 }
-console.log("Pop 100,000 Array Stack timing:", ptime.elapsedTime('parraystack100000').formatted);
+let upstackTime = ptime.elapsedTime('upstack100000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1,000,000 items onto the stack
+ptime.setTime('upstack1000000');
+for(let i = 0; i < 1000000; i++) {
+    uArrayStack.pop('value');
+}
+let upmStackTime = ptime.elapsedTime('upstack1000000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1 item onto the stack
+ptime.setTime('upstack1');
+for(let i = 0; i < 1; i++) {
+    uArrayStack.pop('value');
+}
+let upsStackTime = ptime.elapsedTime('upstack1');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+
+
+
+
+// push 100,000 items onto the stack
+ptime.setTime('bpstack100000');
+for(let i = 0; i < 100000; i++) {
+    bArrayStack.pop('value');
+}
+let bpstackTime = ptime.elapsedTime('bpstack100000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1,000,000 items onto the stack
+ptime.setTime('bpstack1000000');
+for(let i = 0; i < 1000000; i++) {
+    bArrayStack.pop('value');
+}
+let bpmStackTime = ptime.elapsedTime('bpstack1000000');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+// push 1 item onto the stack
+ptime.setTime('bpstack1');
+for(let i = 0; i < 1; i++) {
+    bArrayStack.pop('value');
+}
+let bpsStackTime = ptime.elapsedTime('bpstack1');
+// console.log("Push 100,000 Linked Stack timing:", ptime.elapsedTime('stack100000').formatted);
+
+
+/// Output results
+
+const table = new Table({
+    head: ['Stack Operation', '100,000 items', '1,000,000 items', '1 item']
+});
+
+
+table.push(
+    ['Linked List Stack Push', stackTime.formatted, mStackTime.formatted, sStackTime.formatted],
+    ['Unbounded Array Stack Push', ustackTime.formatted, umStackTime.formatted, usStackTime.formatted],
+    ['Bounded Array Stack Push', bstackTime.formatted, bmStackTime.formatted, bsStackTime.formatted],
+    ['Linked List Stack Pop', pstackTime.formatted, pmStackTime.formatted, psStackTime.formatted],
+    ['Unbounded Array Stack Pop', upstackTime.formatted, upmStackTime.formatted, upsStackTime.formatted],
+    ['Bounded Array Stack Pop', bpstackTime.formatted, bpmStackTime.formatted, bpsStackTime.formatted],
+);
+
+console.log(table.toString());

lib/stacks.js

@@ -1,32 +1,30 @@
-class Stack {
+class LinkedStack {
     constructor () {
-        this.top = {};        
+        this.topNode = null;        
         this.length = 0;
     }
 
     push(data) {
         let node = {
             value: data,
-            prev: this.top
+            prev: this.topNode
         };
-        this.top = node;
+        this.topNode = node;
         this.length++;
         return this.length;        
     }
 
     pop() {
-        if(this.length === 0) {
+        if(this.isEmpty()) {
             return undefined;
         }
 
-        let value = this.top.value;
-        this.top = this.top.prev;
-        this.length--;
-        return value;        
+        this.topNode = this.topNode.prev;
+        this.length--;        
     }
 
-    peek() {
-        return this.top.value;
+    top() {
+        return this.topNode.value;
     }
 
     height() {
@@ -38,7 +36,7 @@ class Stack {
     }
 }
 
-class ArrayStack {
+class UArrayStack {
     constructor() {
         this.stack = [];
     }
@@ -48,10 +46,10 @@ class ArrayStack {
     }
 
     pop() {
-        return this.stack.pop();
+        this.stack.pop();
     }
 
-    peek() {
+    top() {
         return this.stack[this.stack.length - 1];
     }
 
@@ -64,8 +62,61 @@ class ArrayStack {
     }
 }
 
+class BArrayStack {
+    constructor(size) {
+        const DEFAULT_SIZE = 100;
+        let use = !!size ? size : DEFAULT_SIZE;
+        this.stack = [];
+        for(let i = 0; i < use; i++) {
+            this.stack[i] = null;
+        }                             
+        this.topIndex = -1;
+    }
+
+    height() {
+        return this.topIndex + 1;
+    }
+
+    isEmpty() {
+        return this.topIndex === -1 ? true : false;        
+    }
+
+    isFull() {
+        return this.topIndex === this.stack.length - 1 ? true : false;
+    }
+
+    push(item) {
+        if(!this.isFull()) {
+            this.topIndex++;
+            this.stack[this.topIndex] = item;
+            return this.height();
+        } else {
+            throw new Error('Stack too deep');
+        }
+    }
+
+    pop() {
+        if(!this.isEmpty()) {
+            this.stack[this.topIndex] = null;
+            this.topIndex--;
+        } else {
+            throw new Error('Stack already empty');
+        }
+    }
+
+    top() {
+        if(!this.isEmpty()) {
+            return this.stack[this.topIndex];
+        } else {
+            return undefined;
+        }
+    }
+
+}
+
 
 module.exports = {
-    Stack,
-    ArrayStack
+    LinkedStack,
+    UArrayStack,
+    BArrayStack
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "data-theory",
-  "version": "0.0.1",
+  "version": "1.0.0",
   "description": "A collection of data theory and structures in JavaScript.",
   "main": "index.js",
   "repository": "https://github.com/shadowcodex/data-theory.git",
@@ -17,6 +17,7 @@
     "mocha": "^5.2.0"
   },
   "dependencies": {
+    "cli-table": "^0.3.1",
     "quick-ptime": "^1.0.0"
   }
 }

readme.md

@@ -20,8 +20,9 @@ As theories and structures are built, I'll list them under this heading.
 
 > You won't see a todo list or a target list this time around. I'll take suggestions as issues on the repository, but I'm going to focus on building commong structures and items one at a time. One thing I have learned as a developer is never get ahead of yourself, you can get paralyzed with planning and expectations.
 
-- `Stack`: based on a linked list (slow)
-- `ArrayStack`: based on JS array (fast)
+- `LinkedStack`: based on a linked list (slow)
+- `UArrayStack`: based on JS unbounded array (fast)
+- `BArrayStack`: based on JS bounded array (fastest)
 - `Queue`: based on a linked list (fast)
 - `ArrayQueue`: based on JS array (slow)