Test index.

Author: lygstate

src/data-structures/size-balanced-tree.js

@@ -248,7 +248,19 @@
       return Nil;
     }
     return findNodeAtPos(this._root, pos);
-  },
+  };
+
+  exports.SBTree.prototype.getIndex = function(node) {
+    let index = node.left.size;
+    while (node != this._root) {
+      let parent = node.parent;
+      if (parent.right === node) {
+        index += parent.left.size + 1;
+      }
+      node = parent;
+    }
+    return index;
+  };
 
   exports.SBTree.prototype.insert = function(pos, value) {
     if (pos >= this._root.size) {

test/data-structures/size-balanced-tree.spec.js

@@ -100,16 +100,16 @@ describe('SBTree', function () {
 
   it('push and get 100000 elements, remove the array by always remove the first/last element', function () {
     var sTree = new SBTree();
-    for (var i = 0; i < 2000000; ++i) {
+    for (var i = 0; i < 200000; ++i) {
       sTree.push(i);
     }
     checkNil();
-    for (var i = 0; i < 2000000; ++i) {
+    for (var i = 0; i < 200000; ++i) {
       var node = sTree.get(i);
       expect(node.value).toBe(i);
     }
-    expect(sTree._root.height).toBe(21);
-    for (var i = 0; i < 2000000; ++i) {
+    expect(sTree._root.height).toBe(18);
+    for (var i = 0; i < 200000; ++i) {
       expect(sTree.get(0).value).toBe(i);
       var node = sTree.remove(0); // Always remove the first element;
       expect(node.value).toBe(i);
@@ -137,7 +137,6 @@ describe('SBTree', function () {
       var node = sTree.get(i);
       expect(node.value).toBe(expectedArray[i]);
     }
-    console.log(sTree._root.height);
     for (var i = 0; i < 90000; ++i) {
       var removedPos = getRandomInt(0, sTree.size);
       sTree.remove(removedPos);
@@ -147,7 +146,20 @@ describe('SBTree', function () {
       var node = sTree.get(i);
       expect(node.value).toBe(expectedArray[i]);
     }
-    console.log(sTree._root.height);
     checkNil();
   });
+
+  it('test getIndex', function(){
+    var sTree = new SBTree();
+    for (let i = 0; i < 10000; ++i) {
+      let key = i.toString();
+      sTree.push(key);
+    }
+
+    for (let i=0; i<100; ++i) {
+      let item = sTree.get(i);
+      expect(item.value).toBe(i.toString());
+      expect(sTree.getIndex(item)).toBe(i);
+    }
+  });
 });