思路: 这个题写了一个背包的解法,超时了.搜了下题解才发现我根本不会做. 思路参见这个: 其实我们可以这样来考虑,求补集,用全集减掉不能组成2048的集合就是答案了. 因为只要达到2048就可以了,所以求补集会大大减小枚举的次数. 代码: #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <…

HDU 4945 2048 题目链接 题意:给定一个序列,求有多少个子序列能合成2048 思路:把2,4,8..2048这些数字拿出来考虑就能够了,其它数字不管怎样都不能參与组成.那么在这些数字基础上,dp[i][j]表示到第i个数字,和为j的情况数,然后对于每一个数枚举取多少个,就能够利用组合数取进行状态转移,这里有一个剪枝,就是假设加超过2048了,那么后面数字的组合数的和所有都是加到2048上面,能够利用公式一步求解,这种整体复杂度就能够满足题目了.然后这题时限卡得紧啊.10W内的逆元不先…

2048 Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 840    Accepted Submission(s): 199 Problem Description Teacher Mai is addicted to game 2048. But finally he finds it's too hard to get 2048.…

题意:给n(n<=100,000)个数,0<=a[i]<=2048 .一个好的集合要满足,集合内的数可以根据2048的合并规则合并成2048 .输出好的集合的个数%998244353 . 比赛的时候想着1跟3可以合并成4 ....然后就越搞越复杂了.....2048玩得不多的我没有透彻的合并规则概念..... 看了题解写了发,妥妥地TLE...本地随意n=100,000都TLE了... 用dp[i][j]表示当前 i个2^j 的方案数 然后队友提醒优化,就是,当枚举到比如,value =…

2048 Problem Description Teacher Mai is addicted to game 2048. But finally he finds it's too hard to get 2048. So he wants to change the rule: You are given some numbers. Every time you can choose two numbers of the same value from them and merge the…

http://acm.hdu.edu.cn/showproblem.php? pid=4123 Problem Description Bob wants to hold a race to encourage people to do sports. He has got trouble in choosing the route. There are N houses and N - 1 roads in his village. Each road connects two houses,…

http://acm.hdu.edu.cn/showproblem.php?pid=4507 Problem Description 单身! 依旧单身! 吉哥依旧单身! DS级码农吉哥依旧单身! 所以.他生平最恨情人节,无论是214还是77.他都讨厌! 吉哥观察了214和77这两个数,发现: 2+1+4=7 7+7=7*2 77=7*11 终于,他发现原来这一切归根究竟都是由于和7有关!所以,他如今甚至讨厌一切和7有关的数. 什么样的数和7有关呢? 假设一个整数符合以下3个条件之中的一个.那么我…

http://acm.hdu.edu.cn/showproblem.php?pid=3709 Problem Description A balanced number is a non-negative integer that can be balanced if a pivot is placed at some digit. More specifically, imagine each digit as a box with weight indicated by the digit.…

XHXJ's LIS Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2265    Accepted Submission(s): 927 Problem Description #define xhxj (Xin Hang senior sister(学姐)) If you do not know xhxj, then careful…

You Are the One Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3348    Accepted Submission(s): 1524 Problem Description The TV shows such as You Are the One has been very popular. In order to m…