Rikka with Phi 题目连接： http://acm.hdu.edu.cn/showproblem.php?pid=5634 Description Rikka and Yuta are interested …

E. Frog Fights 题目连接： http://www.codeforces.com/contest/625/problem/E Description stap Bender recently visited …

F. The Sum of the k-th Powers 题目连接： http://www.codeforces.com/contest/622/problem/F Description There are well…

C. Electric Charges 题目连接： http://www.codeforces.com/contest/623/problem/C Description Programmer Sasha is a st…

D. Birthday 题目连接： http://www.codeforces.com/contest/623/problem/D Description A MIPT student named Misha has a…

E. Robot Arm 题目连接： http://www.codeforces.com/contest/618/problem/E Description Roger is a robot. He has an arm…

D. Rat Kwesh and Cheese 题目连接： http://www.codeforces.com/contest/621/problem/D Description Wet Shark asked Rat …

F. Double Knapsack 题目连接： http://www.codeforces.com/contest/618/problem/F Description You are given two multise…

F. Xors on Segments 题目连接： http://www.codeforces.com/contest/620/problem/F Description You are given an array w…

D. Professor GukiZ and Two Arrays 题目连接： http://www.codeforces.com/contest/620/problem/D Description Professor …

B. Skills 题目连接： http://www.codeforces.com/contest/613/problem/B Description Lesha plays the recently published…

A. Ebony and Ivory 题目连接： http://www.codeforces.com/contest/633/problem/A Description Dante is engaged in a fig…