其他

題目連結：http://poj.org/problem?id=2096題目意思：一個程式有s個子系統，要找出n種bug。某人一天找n種bug中的一種，求出他找出n種bug並且每個子系統中都有bug的天數的期望。設dp[i][j]表示已經找到了i種bug,並且在j個子系統中出現了的天數期望。則dp[n][s]=0.求出dp[0][0]即為最後的結果。期望從後往前推。第一種：對於每天找到的那個bug在之前找到的i種中並且也在j個子系統中，機率為：i*j/(n*s)第二種：對於這個bug在i種中，並出

題目連結：http://acm.hdu.edu.cn/showproblem.php?pid=4536題目意思：n個國家，每個國家都有一個恐懼值，每個國家屬於一個洲。外星人攻擊k次，每次攻擊三個不同洲的一個國家，問你作為聯盟指揮最多可以抵抗攻擊的次數。每次攻擊你都可以支援一個國家，支援後這個國家的恐懼值-2，但其他兩個國家的恐懼值+2，並且其他兩個國家所在大洲的所有其他國家的恐懼值+1.當有一個國家的恐懼值>5時，任務失敗，不能繼續抵抗攻擊。每個國家的恐懼值最小減少到1。解題思路：dfs暴

Tempter of the BoneTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 50008 Accepted Submission(s): 13420Problem DescriptionThe doggie found a bone in an ancient maze, which fascinated him a lot.

Cow HurdlesTime Limit: 1000MS Memory Limit: 65536KTotal Submissions: 5214 Accepted: 2323DescriptionFarmer John wants the cows to prepare for the county jumping competition, so Bessie and the gang are practicing jumping over hurdles. They are getting

MahjongTime Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2406    Accepted Submission(s): 500Problem DescriptionJapanese Mahjong is a four-player game. The game needs four people to sit around a

BombsTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 326    Accepted Submission(s): 45Problem Description　　Terrorists are around everywhere, they always make troubles by detonating bombs. The

charge-stationTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 616    Accepted Submission(s): 309Problem DescriptionThere are n cities in M^3's empire. M^3 owns a palace and a car and the palace

Max Sum of Max-K-sub-sequenceTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4983    Accepted Submission(s): 1820Problem DescriptionGiven a circle sequence A[1],A[2],A[3]......A[n]. Circle

PipesTime Limit: 5000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 405    Accepted Submission(s): 200Problem DescriptionThe construction of office buildings has become a very standardized task.

Problem 1977 Pandora adventure Accept: 320    Submit: 1034Time Limit: 1000 mSec    Memory Limit : 32768 KB Problem DescriptionThe pollution of the earth is so serious that people can not survive any more. Fortunately, people have found a new planet

Given an integer sequence { an } of length N, you are to cut the sequence into several parts every one of which is a consecutive subsequence of the original sequence. Every part must satisfy that the sum of the integers in the part is not greater

There are tons of problems about integer multiples. Despite the fact that the topic is not original, the content is highly challenging. That’s why we call it “Yet Another Multiple Problem”.In this problem, you’re asked to solve the following

題目連結：http://acm.hdu.edu.cn/showproblem.php?pid=4539題目意思：給一個矩陣，有些位置不能放士兵。每個士兵可以攻擊哈密頓距離恰好為2的所有位置。求最多能放多少個士兵，使得士兵之間不衝突。解題思路：狀態壓縮dp.因為當前位置與前兩行有關，所以把相鄰兩行作為二維狀態，枚舉第i-2行即可得到第i行的狀態。記狀態dp[][i][j]表示當前行狀態為i，前一行狀態為j時，最多能放計程車兵個數。dp[][i][j]=Cal(i)+max(dp[][j][k]);

題目連結：http://acm.hdu.edu.cn/showproblem.php?pid=4101題目大意：給一個矩陣，0表示空的可走，-1寶藏的位置（只有一個），其餘的正整數表示該位置石頭數。甲乙兩個人，輪流玩遊戲。甲先玩，誰先從外面通過空路徑到達了寶藏的位置（不能經過石頭），誰就獲勝。如果不能直接到達寶藏位置，可以從外面通過空到某個位置，拿走該位置上的一個石頭，如果該位置沒有石頭則變成空的可走。解題思路：不錯的BFS。首先如果甲能一步到達寶藏位置，則甲獲勝。否則，一定有一個環包圍著寶藏，

KingTime Limit: 1000MS Memory Limit: 10000KTotal Submissions: 8919 Accepted: 3353DescriptionOnce, in one kingdom, there was a queen and that queen was expecting a baby. The queen prayed: ``If my child was a son and if only he was a sound king.''

Islands and BridgesTime Limit: 4000MS Memory Limit: 65536KTotal Submissions: 7970 Accepted: 2055DescriptionGiven a map of islands and bridges that connect these islands, a Hamilton path, as we all know, is a path along the bridges such that it

題目連結：http://acm.hdu.edu.cn/showproblem.php?pid=4565題目大意：求的值。解題思路：因為(a-1)^2<b<a^2,所以a-1<sqrt(b)<a  所以 0<（a-sqrt(b))^n <1  而p=（a+sqrt(b))^n+(a-sqrt(b))^n為整數，所以Sn=p;再構造遞推關係，Sn*（a+sqrt(b)+a-sqrt(b))=S(n+1)+(a^2-b)*S(n-1)所以S(n+1)=2a*Sn+(

Colored SticksTime Limit: 5000MS Memory Limit: 128000KTotal Submissions: 27792 Accepted: 7346DescriptionYou are given a bunch of wooden sticks. Each endpoint of each stick is colored with some color. Is it possible to align the sticks in a straight

統計難題Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131070/65535 K (Java/Others)Total Submission(s): 13884    Accepted Submission(s): 5971Problem DescriptionIgnatius最近遇到一個難題,老師交給他很多單詞(只有小寫字母組成,不會有重複的單詞出現),現在老師要他統計出以某個字串為首碼的單詞數量(單詞本身也是自己的首碼). 

勝利大逃亡(續)Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4057    Accepted Submission(s): 1342Problem DescriptionIgnatius再次被魔王抓走了(搞不懂他咋這麼討魔王喜歡)……這次魔王汲取了上次的教訓，把Ignatius關在一個n*m的地牢裡，並在地牢的某些地方安裝了帶鎖的門，