weixin_52178708的博客

C. Double-ended Strings You are given the strings a and b, consisting of lowercase Latin letters. You can do any number of the following operations in any order: if |a|>0 (the length of the string a is greater than zero), delete the first character of t

** Anu Has a Function** Anu has created her own function f: f(x,y)=(x|y)−y where | denotes the bitwise OR operation. For example, f(11,6)=(11|6)−6=15−6=9. It can be proved that for any nonnegative numbers x and y value of f(x,y) is also nonnegative. She wo

D. Corrupted Array You are given a number n and an array b1,b2,…,bn+2, obtained according to the following algorithm: some array a1,a2,…,an was guessed; array a was written to array b, i.e. bi=ai (1≤i≤n); The (n+1)-th element of the array b is the sum of t

B. National Project Your company was appointed to lay new asphalt on the highway of length n. You know that every day you can either repair one unit of the highway (lay new asphalt over one unit of the highway) or skip repairing. Skipping the repair is nec