11312 UVA (3)

11392 UVA (4)

http://mirror.codeforces.com/contest/653/problem/E (6)

http://mirror.codeforces.com/contest/769/problem/C 5 //FL:ODD/**** | bfs+greed NICE

10968 UVA (3) //EASY + NICE (bfs withot <=2 nodes)

http://mirror.codeforces.com/contest/796/problem/D (3) //NICE+EASY ... print visited in bfs (not par)

10888 UVA (4) //VERY NICE — but not main technique ... ++ DP /or/ MCMF

http://mirror.codeforces.com/contest/821/problem/D (5) //VERY NICE — Consider only points not GRID

http://www.spoj.com/problems/DIGOKEYS/ (4) //Easy [Nice problem — weird statement]

http://www.spoj.com/problems/SPIKES/ (3) //Easy bfs (# of 's' * 2)

http://www.spoj.com/problems/MULTII/ (4) //VERY NICE: BFS over numbers (K*10+d)%N

http://www.spoj.com/problems/ADV04F1/ (5) //VERY NICE: [imple] ~ N^4*BigConstant

http://www.spoj.com/problems/INVESORT/ (5) //Big limit (really usefull :P)

10977 UVA (3)

928 UVA (3)

13116 UVA (4)

314 UVA (3)

11487 UVA (4)

5622 LA (7)

11931 UVA (5)

http://www.spoj.com/problems/KNMOVE/ 3 //simple knights

http://www.spoj.com/problems/SERGRID/ 3 //almost classical

http://www.spoj.com/problems/NAKANJ/ 3 //Classical chess — KNIGHT

http://www.spoj.com/problems/PUCMM223/ (4) //NICE (but not many languages) — 2 moving [x][y]

http://www.spoj.com/problems/SPIRALGR/ (4) //NICE (not typical) [SIEVE]

http://www.spoj.com/problems/DCEPC706/ (4) //NICE — travelling outside

http://mirror.codeforces.com/contest/35/problem/C (3) //No obstacles [multiple starts]

http://www.spoj.com/problems/ARBITRAG/ (4) //Or Floyd-Warshall

11439 (UVA)

http://mirror.codeforces.com/contest/732/problem/F 7

http://mirror.codeforces.com/contest/700/problem/C 7

http://www.spoj.com/problems/EC_P/ (3) //bridges ONLY

http://www.spoj.com/problems/SUBMERGE/ (3) //Direct articulation

http://www.spoj.com/problems/GRAFFDEF/ (5) //Bridge tree

http://mirror.codeforces.com/contest/715/problem/C 9

http://mirror.codeforces.com/contest/741/problem/D 8

13164 UVA (7)

http://mirror.codeforces.com/contest/752/problem/F 5

http://mirror.codeforces.com/contest/766/problem/E 6

http://mirror.codeforces.com/contest/833/problem/D 7 //Very nice — hard (thinking + imple) + FW

http://www.spoj.com/problems/HOLI/ (4) //VERY NICE: 2*Distances from centroids

12186 UVA (3)

http://mirror.codeforces.com/contest/734/problem/E (5)

http://mirror.codeforces.com/contest/727/problem/A (3)

http://mirror.codeforces.com/contest/723/problem/E (6)

http://mirror.codeforces.com/contest/709/problem/E (6)

http://mirror.codeforces.com/contest/710/problem/E (4)

http://mirror.codeforces.com/contest/758/problem/E (8)

11323 UVA (5)

http://mirror.codeforces.com/contest/760/problem/B (3)

http://mirror.codeforces.com/contest/761/problem/E (6)

http://mirror.codeforces.com/contest/638/problem/B (3) //connect cons. letters

http://mirror.codeforces.com/contest/638/problem/C (4) //greedy idea — easy

http://mirror.codeforces.com/contest/638/problem/D (5) //spec-DAG articulatin

http://mirror.codeforces.com/contest/767/problem/C (4)

http://mirror.codeforces.com/contest/781/problem/C (5)

http://mirror.codeforces.com/contest/794/problem/D (5) //NICE! Right done dfs

http://mirror.codeforces.com/contest/802/problem/K (5) //Slightly DP-like (NICE) TREE

http://mirror.codeforces.com/contest/813/problem/C (3) //Simply 2 DFS: NICE + EASY

http://mirror.codeforces.com/contest/841/problem/D (4) //DFS while tracking "next"

http://mirror.codeforces.com/contest/845/problem/G (5) //Keep track of cycles

http://mirror.codeforces.com/contest/844/problem/E (5) //Post-Order → line, Connect i → N-2: star

http://www.spoj.com/problems/CAC/ (5) //VERY NICE! — Find all cycles in cactus

http://mirror.codeforces.com/contest/849/problem/C (3) //State search by gauss

http://mirror.codeforces.com/contest/846/problem/E (5) //NICE: DFS + some overflow logic

http://www.spoj.com/problems/KOZE/ (3) //NICE: Floods

http://www.spoj.com/problems/RIOI_2_3/ (4) //DFS /OR/ BFS /OR/ DSU [NICE][EASY][BF]

http://www.spoj.com/problems/MAKEMAZE/ (3) //EASY — Simple dfs on grid

http://mirror.codeforces.com/contest/861/problem/F (5) //VERY NICE: Modify dfs tree so it remains connected

http://www.spoj.com/problems/GHOSTS/ (3) //NICE — must remain dag after each QR

http://www.spoj.com/problems/AMR10J/ (5) //VERY NICE! — DFS+DP [DAG with cycles]

http://mirror.codeforces.com/contest/24/problem/A (2)//NICE [DFS-ON-CYCLE]

http://mirror.codeforces.com/contest/29/problem/C (3) //Find begining/end of line (graph)

http://mirror.codeforces.com/contest/29/problem/D (4) //Tree [implementation][simulation]

http://mirror.codeforces.com/contest/716/problem/D 7

12047 UVA 4

11514 UVA 4

http://mirror.codeforces.com/contest/757/problem/F 7

11338 UVA (4)

11374 UVA (4)

11097 UVA (4) //Divide to N*1000 nodes and go!

13172 UVA (5) //6*DJ per query + permutations

10816 UVA (4) //Easy Linear-Search by answer + DJ with path

http://mirror.codeforces.com/contest/827/problem/F 7 //Very nice — Even&Odd

http://www.spoj.com/problems/DELIVER/ (5) //Normalize coordinates + Optimalize

http://www.spoj.com/problems/CCHESS/ (4) //Dijkstra as knight

http://mirror.codeforces.com/contest/723/problem/F 7

13153 UVA (5)

13169 UVA (3)

11987 UVA (3)

11474 UVA (4)

http://mirror.codeforces.com/contest/687/problem/D 6

http://mirror.codeforces.com/contest/680/problem/E 7 //+precalculation/brute force

http://mirror.codeforces.com/contest/766/problem/D 5

http://www.spoj.com/problems/LEXSTR/ (3) //Nice na stringu

http://mirror.codeforces.com/contest/805/problem/C 3 //NICE (dijkstra like :P)

http://www.spoj.com/problems/IITKWPCI/ (3) //VERY NICE

http://www.spoj.com/problems/FRNDCIRC (3) //Classical DSU (NICE for practice)

http://www.spoj.com/problems/FOXLINGS/ (3) Easy — just renumbering

http://www.spoj.com/problems/NITTROAD/ (4) //Process from back

http://www.spoj.com/problems/SHAHBG/ (2) //DSU not needes (simulated by array)

http://mirror.codeforces.com/contest/598/problem/D (3) //Can be solved with DFS too

http://mirror.codeforces.com/contest/9/problem/E (4) //Making one big cycle

http://mirror.codeforces.com/contest/25/problem/D (4) //Could be done linear too

http://mirror.codeforces.com/contest/28/problem/B (4) //NICE [imho bad statement]

http://mirror.codeforces.com/contest/789/problem/D //Adj EG + Self/everything

http://mirror.codeforces.com/contest/21/problem/D (5) //[NICE][EulerTour+DP]

http://mirror.codeforces.com/contest/36/problem/E (6) //VERY NICE [4odd is hardest]

http://www.spoj.com/problems/FASTFLOW/en/ //Raw (no sauce)

4322 — Destroying the bus stations (Live Archive)

11380 — Down Went The Titanic (UVA) //Interesting grid problem

6395 — Surely You Congest (LA) //VERY NICE [slightly advanced]

7204 — Blood groups (LA)

http://mirror.codeforces.com/gym/100963 (Flame of Nucleus — F)

11167 — Monkeys in the Emei Mountain //Also harder (imho)

http://mirror.codeforces.com/problemset/problem/808/F (+BS)

http://mirror.codeforces.com/problemset/problem/653/D (+BS)

13000 — VIP Treatment (+BS)

1242 — Necklace

https://www.deadline24.pl/assets/problemsets/dl24.elim.2017.B.en.pdf (DEADLINE 24 problem — not sure if it can be submited :O)

3487 — Duopoly (Near matching)

http://mirror.codeforces.com/problemset/problem/847/J //Not sure if matching is right solutions but it works [also very near to matching]

http://mirror.codeforces.com/problemset/problem/727/D

http://mirror.codeforces.com/problemset/problem/704/D [Also advanced]

5418 — A Plug for UNIX (LA)

4957 — Fake scoreboard (LA) //If I remember well, other solutions was also possible

1155 — Power Transmission (LOJ) //(classical)

https://www.codechef.com/problems/ROBOTDAG //Ford-Fukherson

10804 — Gopher Strategy (UVA)

11506 — Angry Programmer (UVA) //Nodes division

10511 — Councilling (UVA)

563 — Crimewave

1306 — The K-League (UVA)

1345 — Jamie's Contact Groups

10092 — The Problem with the Problem Setter

Problem B. Roller Coaster Scheduling (GCJ — 2017)

259 — Software Allocation (UVA)

5905 — Pool construction (LA) //Imho harder

10480 — Sabotage

13211 UVA (5) //NICE — FW adding states

http://www.spoj.com/problems/ROHAAN/ (3) //Classical

http://mirror.codeforces.com/contest/25/problem/C (4) //Adding new edges .. need FW principal

http://mirror.codeforces.com/contest/33/problem/B (3) //NICE [dijkstra could work too]

http://mirror.codeforces.com/contest/27/problem/D (5)

11387 (UVA) 4

http://www.spoj.com/problems/VFRIEND2/ (5) //Graph possible check

http://mirror.codeforces.com/contest/859/problem/E (4) //VERY NICE (2 cases: CYCLE [x2] / TREE [x(Size+1)]

http://mirror.codeforces.com/contest/847/problem/C (2) //Forest making Easy&Nice

http://mirror.codeforces.com/contest/863/problem/C (3) //Cycle in states

http://www.spoj.com/problems/DSUBTREE/ (5) //Isomorphism on trees (try all subsets)

http://www.spoj.com/problems/TREEISO/ (4) //Simple isomorphism of trees

http://www.spoj.com/problems/MATCHING/ //Raw (no sauce)

6234 — Tile Cut (LA)

10080 — Gopher II (UVA) //Easy — sympathic

11419 — SAM I AM (UVA) //Grid-Matching

http://mirror.codeforces.com/gym/101485 (Elementary Math — E) //Very nice principal [not that hard]

3673 — Black-White Grid (UVA) //Grid

12927 — Points Cover (UVA)

6851 — The Programmers (LA)

6887 — Book Club //NICE

6571 — It Can Be Arranged

12530 — Game of Tiles

http://mirror.codeforces.com/gym/100820 (Airport — A) //Nice one

http://mirror.codeforces.com/gym/100753 (Bounty Hunterr II — B) //VERY NICE — I refered multiple times to this principal

http://www.spoj.com/problems/NITT4/

http://mirror.codeforces.com/gym/101408 (Cat vs Dog — C)

1171 — Knights in Chessboard (II) (LOJ) //Classical chess

11985 — Prime Independence (UVA)

http://www.spoj.com/problems/SCPC11H/ //Very nice — yet not hard

12644 — Vocabulary

http://mirror.codeforces.com/gym/101047/problem/H

http://mirror.codeforces.com/problemset/problem/659/E

12972 — Cuban Challenge (UVA)

1201 — Taxi Cab Scheme (UVA)

12963 — Astragalus Nitidiflorus

6525 — Attacking rooks (LA)

3415 — Guardian of Decency (LA)

http://www.spoj.com/problems/AMR12A/

12159 — Gun Fight (UVA)

https://www.codechef.com/problems/CHEFYODA //Imho matching is not the crucial part here

12831 — Bob the Builder

http://mirror.codeforces.com/problemset/problem/831/D

11262 — Weird Fence

12549 — Sentry Robots

11138 — Nuts and Bolts

http://www.spoj.com/problems/ADACITY/

http://www.spoj.com/problems/ADAPATH/

http://www.spoj.com/problems/ADAGROW/

http://mirror.codeforces.com/gym/100800 (Aqueduct Construction — A)

10806 — Dijkstra, Dijkstra.

12944 — Earthquake Disaster

12891 — Risk of Trading

11613 — Acme Corporation

https://www.codechef.com/problems/HOGON

http://www.spoj.com/problems/BNMT/ //Solved with MCMF yet I remember I thought normal flows would work too

http://mirror.codeforces.com/problemset/problem/818/G

http://mirror.codeforces.com/problemset/problem/802/C

http://mirror.codeforces.com/contest/863/problem/F (5) //VERY NICE

http://www.spoj.com/problems/COT/ (7) //ON TREE [but very tight TLE]

http://www.spoj.com/problems/GOT/ (5) //ON TREE

http://www.spoj.com/problems/TFRIENDS/ (4) //just scc size

http://www.spoj.com/problems/CAPCITY/ (4) //scc destination [WEAK TC]

http://mirror.codeforces.com/contest/22/problem/E (5) //[NICE][make it strongly connected][SRC>DST]

BLINNET SPOJ (3)

11183 UVA (4) //Directed [need to know algo!]

http://www.spoj.com/problems/ULM09/ (3) //Sum-Kruskal

http://www.spoj.com/problems/IITKWPCG/ (4) //VERY NICE [log instead of price]

http://mirror.codeforces.com/contest/17/problem/B (3) //Spanning tree [no dsu]

11478 UVA (5)

http://mirror.codeforces.com/contest/765/problem/E 5

http://mirror.codeforces.com/contest/770/problem/C 4 //reduce + toposort

http://mirror.codeforces.com/contest/825/problem/E 4 //Toposort from biggest/backward

http://www.spoj.com/problems/CODESPTI/ (6) //VERY NICE — Hard/Weak children

http://mirror.codeforces.com/contest/746/problem/G 5

http://mirror.codeforces.com/contest/750/problem/F 9

http://www.spoj.com/problems/RTREE/ 3 //longest path tree — query

13175 UVA (2) //something like preorder build

http://mirror.codeforces.com/contest/796/problem/C (3) //Just counting — inc by at most 2

http://mirror.codeforces.com/contest/797/problem/D (4) //VERY NICE — sort + D&C all

http://mirror.codeforces.com/contest/805/problem/E (4) //NICE — Treewidth coloring (greedy)

http://mirror.codeforces.com/contest/828/problem/D (3) //Star construction

http://www.spoj.com/problems/TREEDEGREE/ (3) //Degree from euler tree

http://www.spoj.com/problems/UCV2013J/ (3) //Find what is leaf in Binary Tree

http://www.spoj.com/problems/GCPC11J/ (3) //Finding ceter

http://mirror.codeforces.com/contest/34/problem/D (3) //Simple reconstruction + DFS

13089 — Golden Coins (UVA)

http://mirror.codeforces.com/problemset/problem/855/C

http://mirror.codeforces.com/problemset/problem/718/D

https://www.codechef.com/problems/TWOCOINS

https://www.hackerrank.com/contests/101hack35/challenges/road-maintenance/problem

7649 — Performance Review (LA)

http://mirror.codeforces.com/problemset/problem/741/D

http://mirror.codeforces.com/problemset/problem/592/D

https://www.codechef.com/problems/TOMJERGA

http://mirror.codeforces.com/problemset/problem/814/D

1220 — Party at Hali-Bula (UVA)

https://www.hackerrank.com/contests/june-world-codesprint/challenges/r-tree-decoration/problem

12452 — Plants vs. Zombies HD SP (UVA)

http://mirror.codeforces.com/problemset/problem/735/E

https://www.codechef.com/problems/COLTREE

12466 — Ancestors (UVA)

6829 — Intrepid climber (LA)

https://www.hackerrank.com/contests/101hack35/challenges/jeanies-route

12257 — The Queue (UVA)

http://www.spoj.com/problems/ADASALES/

http://mirror.codeforces.com/problemset/problem/805/F

http://mirror.codeforces.com/problemset/problem/763/D

1218 — Perfect Service

3346 — Perfect Domination on Trees (same as above -_-)

12093 — Protecting Zonk

10859 — Placing Lampposts

http://mirror.codeforces.com/problemset/problem/23/E //NICE [but requires big int]

http://mirror.codeforces.com/problemset/problem/14/D (5) //NICE [sorting-one][2DFS]

http://www.spoj.com/problems/TWOPATHS/ (6) //VERY NICE Same as above ~ bigger constraints

http://mirror.codeforces.com/contest/868/problem/E (8) //VERY NICE — HARD — on tree

10937 UVA (4) //find '!' / BFS / TSP — NICE!

10944 UVA (4)

10818 UVA (5) //Easy — but not-easy implementation: ++Dijkstra [LEX!]

http://www.spoj.com/problems/A_W_S_N/ (4) //BFS + TSP (path) — NICE

11930 UVA (4)

http://mirror.codeforces.com/contest/776/problem/D (5)

http://mirror.codeforces.com/contest/733/problem/F 7

11354 UVA (4)

http://www.spoj.com/problems/POLICEMEN/ (3) //simple + small graph

http://www.spoj.com/problems/QTREE2/ (5) //very easy if bin. understrood

http://mirror.codeforces.com/contest/828/problem/F 7 // Differently MST / Outside

http://mirror.codeforces.com/contest/832/problem/D (5) //Classical + Depth /OR/ HLD +ST

http://www.spoj.com/problems/DRTREE/ (5) //NICE [finding ancestor + depths]

http://mirror.codeforces.com/problemset/problem/838/B (6) //VERY NICE [HLD + ET + ST]

http://www.spoj.com/problems/NTICKETS/ (4) //Maximum on path

http://www.spoj.com/problems/GRASSPLA/ (5) //HLD

http://mirror.codeforces.com/contest/855/problem/D (4) //VERY VERY BAD STATEMENT (not so bad problem)