1 
P1  Query on a tree II 
SPOJ 

2 
P2  Query on a tree 
SPOJ 

3 
P3  Greedy Merchants 
Codeforces 
ABBYY Cup 2.0  Hard 
4 
P4  Protect Sheep 
Codeforces 
Codeforces Round #470 (rated, Div. 2, based on VK Cup 2018 Round 1) 
5 
P5  Fafa and the Gates 
Codeforces 
Codeforces Round #465 (Div. 2) 
6 
P6  Seat Arrangements 
Codeforces 
Codeforces Round #460 (Div. 2) 
7 
P7  Position in Fraction 
Codeforces 
Codeforces Round #450 (Div. 2) 
8 
P8  Minimum Sum 
Codeforces 
Testing Round #14 (Unrated) 
9 
P9  Voltage Keepsake 
Codeforces 
VK Cup 2017  Round 2 
10 
P10  Really Big Numbers 
Codeforces 
Educational Codeforces Round 23 
11 
P11  Consecutive Subsequence 
Codeforces 
Codeforces Round #479 (Div. 3) 
12 
P12  Facetook Priority Wall 
Codeforces 
Codeforces Beta Round #67 (Div. 2) 
13 
P13  Registration System 
Codeforces 
Codeforces Beta Round #4 (Div. 2 Only) 
14 
P14  Equal Sums 
Codeforces 
Codeforces Round #486 (Div. 3) 
15 
P15  Prime Swaps 
Codeforces 
Codeforces Round #246 (Div. 2) 
16 
P16  Knight Tournament 
Codeforces 
Codeforces Round #207 (Div. 1) & Codeforces Round #207 (Div. 2) 
17 
P17  Coloring a Tree 
Codeforces 
Codeforces Round #453 (Div. 2) 
18 
P18  Colorful Graph 
Codeforces 
Codeforces Round #151 (Div. 2) 
19 
P19  Biridian Forest 
Codeforces 
Codeforces Round #192 (Div. 1) & Codeforces Round #192 (Div. 2) 
20 
P20  Maze 
Codeforces 
Codeforces Round #222 (Div. 1) & Codeforces Round #222 (Div. 2) 
21 
P21  Unbearable Controversy of Being 
Codeforces 
Codeforces Round #277.5 (Div. 2) 
22 
P22  Cthulhu 
Codeforces 
Codeforces Beta Round #80 (Div. 1 Only) 
23 
P23  Ice Skating 
Codeforces 
Codeforces Round #134 (Div. 1) & Codeforces Round #134 (Div. 2) 
24 
P24  Prime Path 
SPOJ 

25 
P25  Mahmoud and Ehab and the bipartiteness 
Codeforces 
Codeforces Round #435 (Div. 2) 
26 
P26  VALIDATE THE MAZE 
SPOJ 

27 
P27  Herding 
SPOJ 

28 
P28  Xenia and Bit Operations 
Codeforces 
Codeforces Round #197 (Div. 2) 
29 
P29  Sereja and Brackets 
Codeforces 
Codeforces Round #223 (Div. 1) & Codeforces Round #223 (Div. 2) 
30 
P30  Points 
Codeforces 
Codeforces Beta Round #19 
31 
P31  Kquery 
SPOJ Vietnam 

32 
P32  Maximum Sum 
SPOJ 

33 
P33  Can you answer these queries I 
SPOJ 

34 
P34  Can you answer these queries II 
SPOJ 
