major

1 files changed, 48 insertions, 0 deletions

diff --git a/javascripts/Stack.js b/javascripts/Stack.js
new file mode 100644
index 0000000..808dea9
--- /dev/null
+++ b/javascripts/Stack.js
@@ -0,0 +1,48 @@
+/*
+ * Stack
+ *
+ */
+function Stack() {
+	this.a = new Array();
+	this.length = 0;
+}
+
+Stack.prototype.push = function(obj) {
+	this.a.push(obj);
+	this.length++;
+}
+
+Stack.prototype.pop = function() {
+	if (this.isEmpty()) {
+		throw('Pop from empty stack.');
+	}
+	this.length--;
+	return this.a.pop();
+}
+
+Stack.prototype.isEmpty = function() {
+	if (this.length == 0) {
+		return true;
+	}
+	return false;
+}
+
+Stack.prototype.get = function(index) {
+	return this.a[index];
+}
+
+Stack.prototype.copy = function() {
+	var c = ((new Array()).concat(this.a));
+	var ret = new Stack();
+	ret.a = c;
+	ret.length = this.length;
+	return ret;
+}
+
+Stack.prototype.str = function() {
+	ret = '';
+	for (var i=0; i < this.length; i++) {
+		ret += this.a[i].id + ' ';
+	}
+	return ret;
+}