DUAN的专栏

 问题描述：有理数全体为一可数集合。 把表示所有有理数的分数按下列方法进行列举。1/1 1/2 1/3 1/4.....2/1 2/2 2/3....3/1 3/2 ....4/1..............我们以z字型方法给上表的每项编号。特定方法：第一项是1/1，然后是1/2、2/1、3/1、2/2、1/3、1/4、2/3……。编程输入项号N（1  分析

We say that a number is a palindrom if it is the sane when read from left to right or from right to left. The objective of this problem is to verify if a set of given numbers are palindroms in any basis from 2 to 16.

A color reduction is a mapping from a set of discrete colors to a smaller one. The solution to this problem requires that you perform just such a mapping in a standard twenty-four bit RGB color space. The input consists of a target set of sixteen RGB color

<br />Among grandfather��s papers a bill was found:<br />72 turkeys $_679_<br />The first and the last digits of the number that obviously represented the total price of those turkeys are replaced here by blanks (denoted _), for they are faded and are now

Have you ever used file searching tools provided by an operating system? For example, in DOS, if you type "dir *.exe", the OS will list all executable files with extension "exe" in the current directory.

<br />A calendar is a system for measuring time, from hours and minutes, to months and days, and finally to years and centuries. The terms of hour, day, month, year and century are all units of time measurements of a calender system.<br />According to the

FatMouse prepared M pounds of cat food, ready to trade with the cats guarding the warehouse containing his favorite food, JavaBean.

声明：转载或引用本文代码，请务必注明出处！ http://blog.csdn.net/fduan思路分析：此题为一道几何题，可以证明当人墙与右边两条直线所成三角形为等腰三角形时，人墙长度最短。接下来就是非常简单的几何计算了。下面给出我的实现代码，有一点需要注意，即使用三角函数时，有可能得出的人数为负数，这时应输出0。

In the 22nd Century, scientists have discovered intelligent residents live on the Mars. Martians are very fond of mathematics. Every year, they would hold an Arithmetic Contest on Mars (ACM). The task of the contest is to calculate the sum of two 100-digit

A boolean matrix has the parity property when each row and each column has an even sum, i.e. contains an even number of bits which are set. Here's a 4 x 4 matrix which has the parity property: 1 0 1 00 0 0 01 1 1 10 1 0 1The sums of the rows

One measure of ``unsortedness'' in a sequence is the number of pairs of entries that are out of order with respect to each other. For instance, in the letter sequence ``DAABEC'', this measure is 5, since D is greater than four letters to its right and E is

Give a natural number n (1

Tom has a meadow in his garden. He divides it into N * M squares. Initially all the squares were covered with grass. He mowed down the grass on some of the squares and thinks the meadow is beautiful if and only if Not all squares are covered with grass

Convert color images to a gray-level images.

Calculating the least common multiple (LCM) of a set of positive integers.