二分查找实现

Author: imoyao

Diff for: README.md

@@ -26,8 +26,15 @@
 
 ## Algorithms-Python
 
-github trending,暂时没有发现中文版。
+来自 github trending ,暂时没有发现中文版。
 
 [Algorithms-Python](https://github.com/TheAlgorithms/Python)
 
+## Data Structures and Algorithms in Python
+[Data Structures and Algorithms in Python](https://doc.lagout.org/programmation/python/Data%20Structures%20and%20Algorithms%20in%20Python%20[Goodrich,%20Tamassia%20&%20Goldwasser%202013-03-18].pdf)
+
+## 约定
+
+本仓库中代码全部使用`Python3`实现，使用`Linux`操作系统运行。
+
 >蜀之鄙有二僧，其一贫，其一富。贫者语于富者曰：“吾欲之南海，何如？”富者曰：“子何恃而往？”曰：“吾一瓶一钵足矣。”富者曰：“吾数年来欲买舟而下，犹未能也。子何恃而往？”越明年，贫者自南海还，以告富者。富者有惭色。

Diff for: binary_search/binary_search.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Created by imoyao at 2019/5/13 18:33
+
+
+def binary_search(sorted_lists, wanted_item):
+    low_index = 0
+    high_index = len(sorted_lists) - 1
+    count = 0
+    while low_index <= high_index:
+        count += 1
+        mid_index = (low_index + high_index) // 2
+        # print(mid_index)
+        mid_item = sorted_lists[mid_index]
+        if mid_item == wanted_item:
+            print('It takes {0} times to find {1} in index {2}'.format(count, wanted_item, mid_index))
+            return mid_item
+        else:
+            if mid_item < wanted_item:
+                low_index = mid_index + 1
+            else:
+                high_index = mid_index - 1
+    return None
+
+
+if __name__ == '__main__':
+    a = binary_search(list(range(100)), 50)
+    print('ret:', a)