POJ2248-Addition Chains】的更多相关文章

Addition Chains Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5454   Accepted: 2923   Special Judge Description An addition chain for n is an integer sequence <a0, a1,a2,...,am="">with the following four properties: a0 = 1 a…
不知蓝书的标程在说什么,,,,于是自己想了一下...发现自己的代码短的一批... 限制搜索深度+枚举时从大往小枚举,以更接近n+bool判重,避免重复搜索 #include<cstdio> #include<iostream> #include<cstring> #define R register int using namespace std; inline int g() { R ret=; register char ch; while(!isdigit(ch=…
  Addition Chains  An addition chain for n is an integer sequence  with the following four properties: a0 = 1 am = n a0<a1<a2<...<am-1<am For each k ( ) there exist two (not neccessarily different) integers i and j ( ) with ak =ai +aj You a…
1443:[例题4]Addition Chains 题解 注释在代码里 注意优化搜索顺序以及最优化剪枝 代码 #include<iostream> #include<cstdio> #include<algorithm> #include<cmath> #include<cstring> #include<string> #include<queue> #include<functional> using na…
[题目描述] An addition chain for n is an integer sequence with the following four properties: a0 = 1 am = n a0 < a1 < a2 < ... < am-1 < am For each k (1<=k<=m) there exist two (not necessarily different) integers i and j (0<=i, j<=k…
Addition Chains 题面 对于一个数列 \(a_1,a_2 \dots a_{m-1},a_m\) 且 \(a_1<a_2 \dots a_{m-1}<a_m\). 数列中的一个数 \(a_k(2<k<=m)\) ,都有两个数 \(a_i,a_j(1<=i,j<k)\) 满足 \(a_i+a_j=a_k\)( \(i\) 可以等于\(j\) ). 换句话说就是 \(a_k\) 前面有两个数可以加起来等于 \(a_k\)​ .这种数列就是加法链. 题目输入一个…
事先预警:由于我太蒻了,本做法只能在POJ.LOJ等小数据(N<=100)平台上通过,在UVa(洛谷)上大数据并不能通过 戳我获得更好的观看效果 本题不用看,爆搜就是了,但是纯爆搜显然会爆时间,所以要加上一些剪枝 我们来看一下一些常用的剪枝(什么剪枝,其实这么多枝砍掉了,树都没了) 1.最优化剪枝:不存在的,本题求输出方案 2.优化搜索顺序:由于是SPJ,我们对于每个位置上的数字倒着枚举,容易搜索到答案 3.可行性剪枝:需用到数学方法,但是我不会,由于不加该剪枝也能过,所以不讲 最重要的: 卡常…
Description An addition chain for n is an integer sequence  with the following four properties: a0 = 1 am = n a0<a1<a2<...<am-1<am For each k ( ) there exist two (not neccessarily different) integers i and j ( ) with ak =ai +aj You are give…
Description An addition chain for n is an integer sequence with the following four properties: a0 = 1 am = n a0 < a1 < a2 < ... < am-1 < am For each k (1<=k<=m) there exist two (not necessarily different) integers i and j (0<=i, j&…
An addition chain for n is an integer sequence <a0, a1,a2,...,am=""> with the following four properties: a0 = 1 am = n a0 < a1 < a2 < ... < am-1 < am For each k (1<=k<=m) there exist two (not necessarily different) int…