C. Short Program time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Petya learned a new programming language CALPAS. A program in this language always takes one non-negative integer and retur…

贪心 题目看错了...还以为是从操作序列中选5个...然后半个小时没了... 我们把每位分别用0和1带入,看看返回值是什么,然后分类讨论.千万不用特判!!!之前忘了删了就fst... #include<bits/stdc++.h> using namespace std; ; int n, x1, x2, x3; int a[N], mark[N]; ]; int calc(int x, int t) { t = (t << x); ; i <= n; ++i) { ] ==…

传送门:http://codeforces.com/contest/879/problem/C 本题是一个位运算问题——位运算的等价变换. 假设位运算符“&”“|”“^”是左结合的,且优先级相同,则一个表达式:“x@a[1]@a[2]@...@a[n]”,等价于“(...((x@a[1])@a[2])...)@a[n]”.其中,“@”为位运算符“&”“|”“^”. 将表达式“x@a[1]@a[2]@...@a[n]”表示为一个简单的等价形式:“((x&a)|b)^c”,即“x&am…

上一篇博文中 电池温度检测原理和示例代码 ,由于驱动要使用对数函数而从网上参看一个实现 double ln(double a) { ; int k,nk; double x,xx,y; x = (a-)/(a+); xx = x*x; nk = *N+; y = 1.0/nk; ;k--) { nk = nk - ; y = 1.0/nk+xx*y; } return 2.0*x*y; } 尴尬的是当时内核不支持浮点运算所以停滞了, 时间紧迫只能折中先列出各个温度和电压对应表, 通过查表方式处理…

B - B CodeForces - 879B n people are standing in a line to play table tennis. At first, the first two players in the line play a game. Then the loser goes to the end of the line, and the winner plays with the next person from the line, and so on. The…