题目大意:让求长度为n的0 和 1 构成的串中不包含101子串的个数有多少. 这个题当时想了好久,以为是一个规律题,一直在推规律,最后还是wa了,上网一看原来是dp问题, 不过确实递推式挺巧妙的. 递推式dp[i] = 2 * dp[i - 1] - dp[i - 2] + dp[i - 3]; 现在就来推一下这个式子,首先dp[i]就表示当长度为 i 的 的时候满足条件(就是串中不含101)的个数,dp[i] = 2 * dp[i - 1] - {最后两位是10的个数},其中2 * dp[i-…

1363: Count 101 Submit Page    Summary    Time Limit: 1 Sec     Memory Limit: 128 Mb     Submitted: 393     Solved: 154 Description You know YaoYao is fond of his chains. He has a lot of chains and each chain has n diamonds on it. There are two kinds…

https://www.luogu.org/problemnew/show/P2051 一点都不简单的简单dp. 还是从旧行转移到新行,而不是考虑新行从哪些旧行转移吧. #include<bits/stdc++.h> using namespace std; typedef long long ll; namespace combinatorics{ const ll MOD=9999973; //1. 快速幂 x^n %mod inline ll qpow(ll x,ll n,ll mod=…

目录 题目地址 题干 代码和解释 参考 题目地址 hdu1501 题干 代码和解释 最优子结构分析:设这三个字符串分别为a.b.c,如果a.b可以组成c,那么c的最后一个字母必定来自a或者b的最后一个字母.c去除最后一位,就变成由a-1和b或者a和b-1构成c-1的问题. 状态转移方程:DP[i][j]表示c中i个字符来自于a,j个字符来自于b,即由a的前i个字符和b的前j个字符组成c的前i+j个字符.DP[i][j]为1则真,为0则假. /*给3个字符串,让你判断能不能组合前两个字符串来获得第…

Super Jumping! Jumping! Jumping! Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 33384    Accepted Submission(s): 15093 Problem Description Nowadays, a kind of chess game called “Super Jumping!…

题目链接:http://codeforces.com/problemset/problem/455/A 给你n个数,要是其中取一个大小为x的数,那x+1和x-1都不能取了,问你最后取完最大的和是多少. 简单dp,dp[i]表示取i时zui最大和为多少,方程为dp[i] = max(dp[i - 1] , dp[i - 2] + cont[i]*i). #include <bits/stdc++.h> using namespace std; typedef __int64 LL; ; LL a…

Problem H. ICPC QuestTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100500/attachments Description Noura Boubou is a Syrian volunteer at ACM ACPC (Arab Collegiate Programming Contest) since 2011. She graduated from Tishreen Un…

题目链接 这道题也是简单dp里面的一种经典类型,递推式就是dp[i] = min(dp[i-150], dp[i-200], dp[i-350]) 代码如下: #include<iostream> #include <stdio.h> using namespace std; ]; int main() { ; i < ; i++) dp[i] = i; ; i < ; i++) { int minn; ) dp[i] = dp[i - ]; ) dp[i] = min…

J - 简单dp Crawling in process... Crawling failed Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Description It is a little known fact that cows love apples. Farmer John has two apple trees (which are conveni…

I - 简单dp 例题扩展 Crawling in process... Crawling failed Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Description Nowadays, a kind of chess game called “Super Jumping! Jumping! Jumping!” is very popular in HD…