D. Winter is here 题目连接: http://codeforces.com/contest/839/problem/D Description Winter is here at the North and the White Walkers are close. John Snow has an army consisting of n soldiers. While the rest of the world is fighting for the Iron Throne,…
B. Pasha and Phone Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/595/problem/B Description Pasha has recently bought a new phone jPager and started adding his friends' phone numbers there. Each phone number consists of ex…
E. Devu and Flowers 题目连接: http://codeforces.com/contest/451/problem/E Description Devu wants to decorate his garden with flowers. He has purchased n boxes, where the i-th box contains fi flowers. All flowers in a single box are of the same color (hen…
给你一个序列,让你对于所有gcd不为1的子序列,计算它们的gcd*其元素个数之和. 设sum(i)为i的倍数的数的个数,可以通过容斥算出来. 具体看这个吧:http://blog.csdn.net/jaihk662/article/details/77161436. 注意1*C(n,1)+2*C(n,2)+...+n*C(n,n)=n*2^(n-1). #include<cstdio> using namespace std; typedef long long ll; #define MOD…
B. Pasha and Phone Pasha has recently bought a new phone jPager and started adding his friends' phone numbers there. Each phone number consists of exactly n digits. Also Pasha has a number k and two sequences of length n / k (n is divisible by k) a…
#define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; int main(){ ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); int t; cin>>t; while(t--){ long long n,m; cin>>n>>m; ; ans=(n*(n+))>>;//总方案数(无论…
