add array stuff and stack stuff

organize more

Author: williscool

c/array_pointers.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#define NUM_ELEMENTS 5 // http://stackoverflow.com/a/13645995/511710
+
+// http://en.wikipedia.org/wiki/C_%28programming_language%29#Array.E2.80.93pointer_interchangeability 
+
+int i;
+
+int arr[NUM_ELEMENTS];
+
+char* arr_addr = arr;
+
+int main()  {
+  
+  for ( i; i < NUM_ELEMENTS; i++) {
+    
+    arr[i] = i + 20;
+    
+    printf("arr[%d] val: %d \n", i , arr[i]);
+    // http://boredzo.org/pointers/
+    
+    printf("*(arr + i): %d \n\n", *(arr_addr + i * sizeof(int)));
+  }
+  
+  return 0;
+}

javascript/BST_README.md javascript/data_structures/bst/BST_README.md

@@ -0,0 +1,32 @@
+var assert = require('assert');
+
+function Stack() {
+	this.items = [];
+	this.stack_top_index = 0;
+	this.push = function (thing) {
+		this.stack_top_index++;
+		this.items[this.stack_top_index] = thing;
+	}
+	
+	this.pop = function (thing) {
+		if(this.stack_top_index > 0){
+		  var top_item =  this.items[this.stack_top_index];
+		  this.stack_top_index--; 
+			return top_item;
+		} else{
+			throw Error("stack empty");
+		}
+	}
+}
+
+var stack = new Stack();
+
+stack.push(42);
+
+
+assert(stack.stack_top_index == 1 , "stack has one item on it");
+
+var num = stack.pop();
+
+assert(num == 42 , "correct number is returned from stack");
+assert(stack.stack_top_index === 0 , "zero items on stack");