From e968ea686f51200f1b3e959cb154350b29aba17c Mon Sep 17 00:00:00 2001
From: Nova <nova.xu@bittic.org>
Date: Fri, 28 Dec 2018 23:30:35 +0800
Subject: [PATCH] =?UTF-8?q?=E5=8A=A0=E5=85=A5=E9=BB=98=E5=85=8B=E6=A0=B9?=
 =?UTF-8?q?=E8=AE=A1=E7=AE=97=E5=87=BD=E6=95=B0?=
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

---
 index.js | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/index.js b/index.js
index 66c8207..6ec0471 100644
--- a/index.js
+++ b/index.js
@@ -364,6 +364,36 @@ module.exports = {
     return null
   }
   ,
+  getMerkleRoot:function(todoHashList, option){
+    //深拷贝传入数组，防止引用对象被改变
+    let hashList = [...todoHashList]
+    if(!Array.isArray(hashList))
+      return null
+    var border = hashList.length;
+    if(border == 0)
+      return this.hash('')
+    if(border == 1)
+      return this.hash(hashList[0]);
+    while(1){
+      let i = 1,j = 0;
+      for(; i < border; i = i + 2){
+        hashList[j] = this.hash(hashList[i - 1] + hashList[i]);
+        if(border == 2){
+          return hashList[0];
+        }
+        if(i + 1 == border) break;
+        j = j + 1;
+        if(i + 2 == border){
+          i = i + 1;
+          hashList[j] = this.hash(hashList[i]);
+          break;
+        }
+      }
+      border = j + 1;
+    }  
+    return hashList 
+  }
+  ,
   distanceSig:function(hash, sig){ // hash为64hex字符，sig为128hex字符。返回用hex表达的距离。
     if (this.isSignature(sig) && this.isHash(hash)){
       var hashSig=this.hash(sig) // 把签名也转成32字节的哈希，同样长度方便比较