add 215 cpp solution

DivideConquer/215_KthLargestElementArray.cpp

@@ -0,0 +1,52 @@
+/*
+ * @Author: [email protected]
+ * @Last Modified time: 2016-03-31 10:09:26
+ */
+
+class Solution {
+public:
+    int partition(vector<int> &nums, int begin, int end) {
+        int pivot = nums[begin];
+        int pivot_index = begin;
+        for(int i=begin+1; i!=end;i++){
+            if(nums[i] >= pivot){
+                pivot_index+=1;
+                if(pivot_index != i){
+                    swap(nums[i], nums[pivot_index]);
+                }
+            }
+        }
+        swap(nums[begin], nums[pivot_index]);
+        return pivot_index;
+    }
+
+    int findKthLargest(vector<int> &nums, int k) {
+        return find_k(nums, 0, nums.size(), k);
+    }
+
+    int find_k(vector<int> &nums, int begin, int end, int k){
+        if( k<=0 || begin>end-1){
+            return -1;
+        }
+        int position = partition(nums, begin, end);
+        int left_length = position-begin;
+        if(left_length== k-1){
+            return nums[position];
+        }
+        else if(left_length > k-1){
+            return find_k(nums, begin, position, k);
+        }
+        else{
+            return find_k(nums, position+1, end, k-left_length-1);
+        }
+    }
+};
+
+"""
+[1]
+1
+[3,2,1,5,6,4]
+2
+[1,2,1,3,9]
+2
+"""

DivideConquer/215_KthLargestElementArray.py

@@ -30,4 +30,6 @@ def findKthLargest_2(self, nums, k):
 1
 [3,2,1,5,6,4]
 2
+[1,2,1,3,9]
+2
 """

More.md

@@ -0,0 +1,9 @@
+# Binary Indexed Trees
+
+
+相关题目： [s307. Range Sum Query - Mutable](https://leetcode.com/problems/range-sum-query-mutable/)
+
+参考： 
+[夜深人静写算法（三） - 树状数组](http://www.cppblog.com/menjitianya/archive/2015/11/02/212171.html)
+
+

Week07/49.py

@@ -1,5 +1,8 @@
-#! /usr/bin/env python
 # -*- coding: utf-8 -*-
+# @Author: xuelangZF
+# @Date:   2015-10-20 23:43:28
+# @Last Modified by:   xuelangZF
+# @Last Modified time: 2016-03-26 10:21:40
 
 
 class Solution(object):

Week07/50.py

@@ -1,5 +1,8 @@
 #! /usr/bin/env python
 # -*- coding: utf-8 -*-
+# @Author: [email protected]
+# @Date:   2015-10-20 23:43:28
+# @Last Modified time: 2016-03-26 10:22:44
 
 
 class Solution(object):