随笔分类 -  动态规划

摘要：Super Jumping! Jumping! Jumping!Time Limit: 2000/1000 MS (Java/Others)Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 23328Accepted Subm... 阅读全文

摘要：Crossed MatchingsTime Limit: 2 Seconds Memory Limit: 65536 KBThere are two rows of positive integer numbers. We can draw one line segment between any... 阅读全文

摘要：Anniversary partyTime Limit:1000MSMemory Limit:32768KB64bit IO Format:%I64d & %I64uSubmitStatusAppoint description:DescriptionThere is going to be a p... 阅读全文

摘要：DescriptionQuestion 1: Is Bigger Smarter?The ProblemSome people think that the bigger an elephant is, the smarter it is. To disprove this, you want to... 阅读全文

摘要：DescriptionUnidirectional TSPBackgroundProblems that require minimum paths through some domain appear in many different areas of computer science. For... 阅读全文

摘要：DescriptionCutting SticksYou have to cut a wood stick into pieces. The most affordable company, The Analog Cutting Machinery, Inc. (ACM), charges mone... 阅读全文

摘要：DescriptionStacking BoxesBackgroundSome concepts in Mathematics and Computer Science are simple in one or two dimensions but become more complex when ... 阅读全文

摘要：Jzzhu and NumbersTime Limit:2000MSMemory Limit:262144KB64bit IO Format:%I64d & %I64uSubmitStatusAppoint description:DescriptionJzzhu havennon-negative... 阅读全文

摘要：Dudu is a very starving possum. He currently stands in the first shelf of a fridge. This fridge iscomposed of N shelves, and each shelf has a number Q... 阅读全文

摘要：An Easy GameTime Limit: 2 Seconds Memory Limit: 65536 KBOne day, Edward and Flandre play a game. Flandre will show two 01-strings s1 and s2, the leng... 阅读全文

摘要：Divide ChocolateTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1632Accepted Submission(s): 765Pro... 阅读全文

摘要：题目大意：一个字符串，可以分解成若干英语单词的连接（单词可以重复使用），求有多少种方法？#include#include#include#includeusing namespace std;const int maxl=300005;const int maxwn=4005;const int maxwl=105;const int MOD=20071027;const int maxnode=400005;const int sigma_size=26;struct Trie{ int ch[maxnode][sigma_size]; int val[maxnode]; ... 阅读全文

摘要：Good NumbersTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 603Accepted Submission(s): 221 Problem DescriptionIf we sum up every digit of a number and the result can be exactly divided by 10, we say this number is a good number. You are required t 阅读全文

摘要：题目大意：给一个正整数N，每次可以在不超过N的素数中随机选择一个P，如果P是N的约数，则把N变成N/p,否则N不变，问平均情况下需要多少次随机选择，才能把N变成1？分析：根据数学期望的线性和全期望公式可以为每个状态列出一个方程，例如： f(x)=1+f(6)*1/3+f(3)*1/3+f(2)*1/3等式右边的最前面的“1”是指第一次转移，而后面的几项是后续的转移，用全期望公式展开，一般地，设不超过x的素数有p个，其中有g个是x的因子，则f(x)=1+f(x)*(1-g/p)+Σf(x/y)/p边界f(1)=0。移项后整理得f(x)=(Σf(x/y)+p)/g因为x/y#include#inc 阅读全文