【题目】
You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
Follow up:
Could you do this in-place?
【题意】
给定一个nXn的二维矩阵，按时钟方向旋转90度，不能使用额外的数据结构
【思路】
从外向内逐层旋转...
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其他好文 时间：
2014-05-26 05:50:25
阅读次数：
266
Background
Some concepts in Mathematics and Computer Science are simple in one or two dimensions but become more complex when extended to arbitrary dimensions. Consider solving differential equations...
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其他好文 时间：
2014-05-26 04:31:34
阅读次数：
234
Summation of primes
Problem 10
The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
Find the sum of all the primes below two million.
还是使用Sieve of Eratosthenes 算法
我的python代码如下：
...
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其他好文 时间：
2014-05-26 03:40:15
阅读次数：
243
Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have
exact...
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其他好文 时间：
2014-05-25 00:46:51
阅读次数：
229
【题目】
Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
For example,
Given the following matrix:
[
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
]
You should return [1,2,3,6,9,8,7,4,5].
【题意】
螺旋输出MxN...
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其他好文 时间：
2014-05-24 23:11:02
阅读次数：
279
【题目】
Given an array of non-negative integers, you are initially positioned at the first index of the array.
Each element in the array represents your maximum jump length at that position.
Determine if you are able to reach the last index.
For example:...
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其他好文 时间：
2014-05-24 20:44:39
阅读次数：
221
Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume
that each input would have exact...
分类：
其他好文 时间：
2014-05-24 20:43:37
阅读次数：
341
【题目】
The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.
Given an integer n, return all distinct solutions to the n-queens puzzle.
Each solution contains a distinct board configuratio...
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其他好文 时间：
2014-05-24 17:12:32
阅读次数：
237
【题目】
Given an array of non-negative integers, you are initially positioned at the first index of the array.
Given a collection of intervals, merge all overlapping intervals.
For example,
Given [1,3],[2,6],[8,10],[15,18],
return [1,6],[8,10],[15,18].
...
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其他好文 时间：
2014-05-24 14:18:27
阅读次数：
193
