1 
P1  Bits 
Codeforces 
Codeforces Round #276 (Div. 1) & Codeforces Round #276 (Div. 2) 
2 
P2  Raising Bacteria 
Codeforces 
Codeforces Round #320 (Div. 2) [Bayan ThanksRound] 
3 
P3  Fedor and New Game 
Codeforces 
Codeforces Round #267 (Div. 2) 
4 
P4  Points on Line 
Codeforces 
Codeforces Round #153 (Div. 1) & Codeforces Round #153 (Div. 2) 
5 
P5  Hamburgers 
Codeforces 
Codeforces Round #218 (Div. 2) 
6 
P6  Pipeline 
Codeforces 
Codeforces Round #176 (Div. 2) 
7 
P7  Worms 
Codeforces 
Codeforces Round #271 (Div. 2) 
8 
P8  Burning Midnight Oil 
Codeforces 
Codeforces Round #112 (Div. 2) 
9 
P9  Multiplication Table 
Codeforces 
Codeforces Round #256 (Div. 2) 
10 
P10  Tennis Game 
Codeforces 
Codeforces Round #283 (Div. 2) & Codeforces Round #283 (Div. 1) 
11 
P11  You're Given a String... 
Codeforces 
Codeforces Beta Round #23 
12 
P12  Guess Your Way Out! 
Codeforces 
Codeforces Round #287 (Div. 2) 
13 
P13  Tavas and Karafs 
Codeforces 
Codeforces Round #299 (Div. 2) & Codeforces Round #299 (Div. 1) 
14 
P14  Cellular Network 
Codeforces 
Educational Codeforces Round 15 
15 
P15  They Are Everywhere 
Codeforces 
Codeforces Round #364 (Div. 2) 
16 
P16  Aggressive cows 
SPOJ 

17 
P17  The Monkey and the Oiled Bamboo 
UVA 

18 
P18  Helping Fill Bates 
UVA 
