http://www.codeforces.com/contest/628/problem/A
A tennis tournament with n participants is running. The participants are playing by an olympic system, so the winners move on and the losers drop out.
The tournament takes place in the following way (below, m is the number of the participants of the current round):
let k be the maximal power of the number 2 such that k ≤ m,
k participants compete in the current round and a half of them passes to the next round, the other m - k participants pass to the next round directly,
when only one participant remains, the tournament finishes.
Each match requires b bottles of water for each participant and one bottle for the judge. Besides p towels are given to each participant for the whole tournament.
Find the number of bottles and towels needed for the tournament.
Note that it's a tennis tournament so in each match two participants compete (one of them will win and the other will lose).
The only line contains three integers n, b, p (1 ≤ n, b, p ≤ 500) — the number of participants and the parameters described in the problem statement.
Print two integers x and y — the number of bottles and towels need for the tournament.
5 2 3
20 15
有两种水,n个人参加比赛
每次都会选择出小于等于n的最大2的倍数,然后让这些人比赛,每个参加比赛的人可以获得b瓶A水,裁判也得有一瓶A水
然后每个人都会获得p瓶B水
然后问你打完所有比赛后,需要多少瓶A水,多少瓶B水
A题就不要想太多,直接暴力吧……
虽然O(1)公式也有
#include<bits/stdc++.h>
using namespace std;
vector<int> two;
int main()
{
long long n,b,p;
cin>>n>>b>>p;
long long ans = 0,ans2 = n*p;
while(n>1)
{
int t = (n)/2*2;
ans+=t*b+t/2;
n-=t/2;
}
cout<<ans<<" "<<ans2<<endl;
}