Written by  on March 27, 2015

POJ2663 Tri Tiling Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 8737 Accepted: 4554 Description In how many ways can you tile a 3xn rectangle with 2×1 dominoes?

[Read more...]


Written by  on December 26, 2014

UVAOJ11234||POJ3367 Expressions Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 2591 Accepted: 850 Description Arithmetic expressions are usually written with the operators in between the two operands (which is called infix notation). For example, (x+y)*(z-w) is an arithmetic expression in infix notation. However, it is easier to write a program to evaluate an expression if the expression is written in postfix notation (also known as reverse Polish notation). In postfix notation, an operator is written behind its two operands, which may be expressions themselves. For example, x y + z w – * is a postfix notation of the arithmetic expression given above. Note that in this case parentheses are not required.

[Read more...]


Written by  on December 26, 2014

UVAOJ || POJ3195 Generalized Matrioshkas Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 1835 Accepted: 538 Description Vladimir worked for years making matrioshkas, those nesting dolls that certainly represent truly Russian craft. A matrioshka is a doll that may be opened in two halves, so that one finds another doll inside. Then this doll may be opened to find another one inside it. This can be repeated several times, till a final doll – that cannot be opened – is reached.

[Read more...]


Written by  on December 20, 2014

POJ1840 Eqs Time Limit: 5000MS Memory Limit: 65536K Total Submissions: 14507 Accepted: 7122 Description Consider equations having the following form:

[Read more...]


Written by  on October 12, 2014

POJ2085 Inversion Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 4004 Accepted: 1790 Description The inversion number of an integer sequence a1, a2, . . . , an is the number of pairs (ai, aj) that satisfy i < j and ai > aj . Given n and the inversion number m, your task is to find the smallest permutation of the set { 1, 2, . . . , n }, whose inversion number is exactly m.

[Read more...]


Written by  on October 10, 2014

POJ2084 Game of Connections Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 7901 Accepted: 3973 Description This is a small but ancient game. You are supposed to write down the numbers 1, 2, 3, . . . , 2n – 1, 2n consecutively in clockwise order on the ground to form a circle, and then, to draw some straight line segments to connect them into number pairs. Every number must be connected to exactly one another.

[Read more...]


Written by  on September 17, 2014

最近改变刷题思路,开始跟Stanford的CS97SI来刷POJ,这样的话感觉比单纯地按照题目分类来刷更有效率一点 POJ2140 Herd Sums

[Read more...]


Written by  on August 29, 2014

POJ1125 Stockbroker Grapevine Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 31827 Accepted: 17443 Description Stockbrokers are known to overreact to rumours. You have been contracted to develop a method of spreading disinformation amongst the stockbrokers to give your employer the tactical edge in the stock market. For maximum effect, you have to spread the rumours in the fastest possible way.

[Read more...]


Written by  on August 22, 2014

POJ1062 昂贵的聘礼 Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 41914 Accepted: 12245 Description 年轻的探险家来到了一个印第安部落里。在那里他和酋长的女儿相爱了,于是便向酋长去求亲。酋长要他用10000个金币作为聘礼才答应把女儿嫁给他。探险家拿不出这么多金币,便请求酋长降低要求。酋长说:”嗯,如果你能够替我弄到大祭司的皮袄,我可以只要8000金币。如果你能够弄来他的水晶球,那么只要5000金币就行了。”探险家就跑到大祭司那里,向他要求皮袄或水晶球,大祭司要他用金币来换,或者替他弄来其他的东西,他可以降低价格。探险家于是又跑到其他地方,其他人也提出了类似的要求,或者直接用金币换,或者找到其他东西就可以降低价格。不过探险家没必要用多样东西去换一样东西,因为不会得到更低的价格。探险家现在很需要你的帮忙,让他用最少的金币娶到自己的心上人。另外他要告诉你的是,在这个部落里,等级观念十分森严。地位差距超过一定限制的两个人之间不会进行任何形式的直接接触,包括交易。他是一个外来人,所以可以不受这些限制。但是如果他和某个地位较低的人进行了交易,地位较高的的人不会再和他交易,他们认为这样等于是间接接触,反过来也一样。因此你需要在考虑所有的情况以后给他提供一个最好的方案。

[Read more...]


Written by  on August 19, 2014

POJ3259 Wormholes Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 37982 Accepted: 13985 Description While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way path that delivers you to its destination at a time that is BEFORE you entered the wormhole! Each of FJ’s farms comprises N (1 ≤ N ≤ 500) fields conveniently numbered 1..N, M (1 ≤ M ≤ 2500) paths, and W (1 ≤ W ≤ 200) wormholes.

[Read more...]