http://poj.org/problem?id=3233
ps转：
用二分方法求等比数列前n项和：即
原理：
(1)若n==0
(2)若n%2==0
(3)若n%2==1
代码如下：
LL sum(LL p,LL n)
{
if(n==0) return 1;
i...
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其他好文 时间：
2014-06-15 20:01:44
阅读次数：
210
题目
Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums
to T.
The same repeated number may be chosen from C un...
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其他好文 时间：
2014-06-15 20:00:18
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185
Given a binary tree and a sum, find all root-to-leaf paths where each path's
sum equals the given sum.
For example:
Given the below binary tree and
sum = 22,
5
...
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其他好文 时间：
2014-06-15 19:55:39
阅读次数：
191
Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.
For example:
Given the below binary tree and sum
...
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其他好文 时间：
2014-06-15 19:26:23
阅读次数：
207
题目
Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers
sums to T.
Each number in C may only be used once in...
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其他好文 时间：
2014-06-15 19:24:21
阅读次数：
229
题目
The count-and-say sequence is the sequence of integers beginning as follows:
1, 11, 21, 1211, 111221, ...
1 is read off as "one
1" or 11.
11 is read off as "two
1s" or 21.
21 i...
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其他好文 时间：
2014-06-15 18:51:33
阅读次数：
220
Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that
adding up all the values along the path equals the given sum.
For example:
Given the below bin...
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其他好文 时间：
2014-06-15 09:34:35
阅读次数：
226
题目
Given two numbers represented as strings, return multiplication of the numbers as a string.
Note: The numbers can be arbitrarily large and are non-negative.
方法
将num1与0-9相乘的结果存...
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其他好文 时间：
2014-06-14 06:08:30
阅读次数：
229
真的被这道题目恶心到了。。。281行代码。。。比一个模拟题还费事。。。
为了方便起见，在数列的前面和后面都加一个0点。
add x ：把第k2+2个点旋转至root1.然后sum[root10]+=x;
reverse：把第k1+2个点旋转至root1.然后rev[root10]^=1;
insert x:得到第2个点，然后在第2个点之后插入x。
delete
：把第1个点旋...
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其他好文 时间：
2014-06-14 00:54:26
阅读次数：
324
Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.
Note: You can only move either down or right at...
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其他好文 时间：
2014-06-13 20:36:56
阅读次数：
280
