zoukankan      html  css  js  c++  java
  • codeforces 552 C Vanya and Scales

    这个题的意思就是给出一个数m。以及一个以1为首元素。w为比例常数的等比数列,数列长度为101,数列中每一个数字最多仅仅能用一次。问是否存在xa+wb+……=wc+wd+……+we+m。
    非常显然,换句话说就是问,是否存在m=wa+wb+……+wf-wc-wd-……-we。再进行化简就能够得到。是在问,是否存在m=((((wh±1)wi±1)±1)wj±1)wk……。

    那么非常显然可以进行搜索,比方说用广搜,每次当前的m±1中若有因子w就所有约掉,然后丢到队列中,否则就不用管,仅仅要队列中可以出现1,那么这样的情况就是存在的。反之就是不存在。


    #include<map>
    #include<string>
    #include<cstring>
    #include<cstdio>
    #include<cstdlib>
    #include<cmath>
    #include<queue>
    #include<vector>
    #include<iostream>
    #include<algorithm>
    #include<bitset>
    #include<climits>
    #include<list>
    #include<iomanip>
    #include<stack>
    #include<set>
    using namespace std;
    int cnt(int w,int x)
    {
    	while(x%w==0)
    		x/=w;
    	return x;
    }
    queue<int>qq;
    bool bfs(int w,int m)
    {
    	int t=cnt(w,m);
    	if(t!=m)
    		qq.push(t);
    	else
    		qq.push(m);
    	while(qq.size())
    	{
    		t=qq.front();
    		qq.pop();
    		if(t==1)
    			return 1;
    		int t1=cnt(w,t+1);
    		if(t1!=t+1)
    			qq.push(t1);
    		t1=cnt(w,t-1);
    		if(t1!=t-1)
    			qq.push(t1);
    	}
    	return 0;
    }
    int main()
    {
    	int w,m;
    	cin>>w>>m;
    	if(bfs(w,m))
    		puts("YES");
    	else
    		puts("NO");
    }



    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    Vanya has a scales for weighing loads and weights of masses w0, w1, w2, ..., w100 grams where w is some integer not less than 2(exactly one weight of each nominal value). Vanya wonders whether he can weight an item with mass m using the given weights, if the weights can be put on both pans of the scales. Formally speaking, your task is to determine whether it is possible to place an item of mass m and some weights on the left pan of the scales, and some weights on the right pan of the scales so that the pans of the scales were in balance.

    Input

    The first line contains two integers w, m (2 ≤ w ≤ 1091 ≤ m ≤ 109) — the number defining the masses of the weights and the mass of the item.

    Output

    Print word 'YES' if the item can be weighted and 'NO' if it cannot.

    Sample test(s)
    input
    3 7
    
    output
    YES
    
    input
    100 99
    
    output
    YES
    
    input
    100 50
    
    output
    NO
    
    Note

    Note to the first sample test. One pan can have an item of mass 7 and a weight of mass 3, and the second pan can have two weights of masses 9 and 1, correspondingly. Then 7 + 3 = 9 + 1.

    Note to the second sample test. One pan of the scales can have an item of mass 99 and the weight of mass 1, and the second pan can have the weight of mass 100.

    Note to the third sample test. It is impossible to measure the weight of the item in the manner described in the input.


  • 相关阅读:
    关于oracle的导入数据流程,以及错误解决
    解决 lombok 和 freemarker 下载慢问题 以及安装方法
    解决maven项目没有Maven Dependencies
    将maven仓库改为阿里仓库
    Dos攻击和校网渗透
    KaliLinux切换python版本
    Kali国内更新源
    linux安装jdk(.rpm)
    Centos 关于 mysql 命令
    Linux删除命令
  • 原文地址:https://www.cnblogs.com/tlnshuju/p/6994734.html
Copyright © 2011-2022 走看看