CSES Problem Set

Source: cses.fi/problemset Total Problems: 300+

The CSES Problem Set is a collection of algorithmic programming problems maintained by the University of Helsinki. It covers a wide range of topics in competitive programming.

📊 Progress

Introductory Problems (19)

#	Problem	Link
1	Weird Algorithm	cses.fi/1068
2	Missing Number	cses.fi/1083
3	Repetitions	cses.fi/1069
4	Increasing Array	cses.fi/1094
5	Permutations	cses.fi/1070
6	Number Spiral	cses.fi/1071
7	Two Knights	cses.fi/1072
8	Two Sets	cses.fi/1092
9	Bit Strings	cses.fi/1617
10	Trailing Zeros	cses.fi/1618
11	Coin Piles	cses.fi/1754
12	Palindrome Reorder	cses.fi/1755
13	Gray Code	cses.fi/2205
14	Tower of Hanoi	cses.fi/2165
15	Creating Strings	cses.fi/1622
16	Apple Division	cses.fi/1623
17	Chessboard and Queens	cses.fi/1624
18	Digit Queries	cses.fi/2431
19	Grid Paths	cses.fi/1625

Sorting and Searching (35)

#	Problem	Link
1	Distinct Numbers	cses.fi/1621
2	Apartments	cses.fi/1084
3	Ferris Wheel	cses.fi/1090
4	Concert Tickets	cses.fi/1091
5	Restaurant Customers	cses.fi/1619
6	Movie Festival	cses.fi/1629
7	Sum of Two Values	cses.fi/1640
8	Maximum Subarray Sum	cses.fi/1643
9	Stick Lengths	cses.fi/1074
10	Missing Coin Sum	cses.fi/2183
11	Collecting Numbers	cses.fi/2216
12	Collecting Numbers II	cses.fi/2217
13	Playlist	cses.fi/1141
14	Towers	cses.fi/1073
15	Traffic Lights	cses.fi/1163
16	Josephus Problem I	cses.fi/2162
17	Josephus Problem II	cses.fi/2163
18	Nearest Smaller Values	cses.fi/1645
19	Subarray Sums I	cses.fi/1660
20	Subarray Sums II	cses.fi/1661
21	Subarray Divisibility	cses.fi/1662
22	Array Division	cses.fi/1085
23	Sliding Window Median	cses.fi/1076
24	Sliding Window Cost	cses.fi/1077
25	Movie Festival II	cses.fi/1632
26	Maximum Subarray Sum II	cses.fi/1644
27	Subarray Distinct Values	cses.fi/2428
28	Array Description	cses.fi/1744
29	Factory Machines	cses.fi/1620
30	Tasks and Deadlines	cses.fi/1631
31	Reading Books	cses.fi/1631
32	Creating Strings	cses.fi/1622
33	Apple Division	cses.fi/1623
34	Grid Paths	cses.fi/1625
35	Palindrome Reorder	cses.fi/1755

Dynamic Programming (19)

#	Problem	Link
1	Dice Combinations	cses.fi/1633
2	Minimizing Coins	cses.fi/1634
3	Coin Combinations I	cses.fi/1635
4	Coin Combinations II	cses.fi/1636
5	Removing Digits	cses.fi/1637
6	Grid Paths	cses.fi/1638
7	Book Shop	cses.fi/1158
8	Array Description	cses.fi/1746
9	Counting Towers	cses.fi/2413
10	Edit Distance	cses.fi/1639
11	Rectangle Cutting	cses.fi/1744
12	Money Sums	cses.fi/1745
13	Removal Game	cses.fi/1097
14	Two Sets II	cses.fi/1093
15	Increasing Subsequence	cses.fi/1145
16	Projects	cses.fi/1140
17	Elevator Rides	cses.fi/1653
18	Counting Tilings	cses.fi/2181
19	Graph Paths I	cses.fi/1723

Graph Algorithms (36)

#	Problem	Link
1	Counting Rooms	cses.fi/1192
2	Labyrinth	cses.fi/1193
3	Building Roads	cses.fi/1194
4	Message Route	cses.fi/1667
5	Building Teams	cses.fi/1668
6	Round Trip	cses.fi/1669
7	Monsters	cses.fi/1195
8	Shortest Routes I	cses.fi/1671
9	Shortest Routes II	cses.fi/1672
10	High Score	cses.fi/1673
11	Flight Discount	cses.fi/1675
12	Cycle Finding	cses.fi/1197
13	Flight Routes	cses.fi/1674
14	Road Reparation	cses.fi/1675
15	Road Construction	cses.fi/1676
16	Flight Routes Check	cses.fi/1682
17	Planets and Kingdoms	cses.fi/1683
18	Giant Pizza	cses.fi/1684
19	Coin Collector	cses.fi/1686
20	Mail Delivery	cses.fi/1693
21	De Bruijn Sequence	cses.fi/1692
22	Knight Moves	cses.fi/1694
23	Book Shop	cses.fi/1158
24	Array Description	cses.fi/1746
25	Projects	cses.fi/1140
26	Elevator Rides	cses.fi/1653
27	Counting Tilings	cses.fi/2181
28	Course Schedule	cses.fi/1679
29	Longest Flight Route	cses.fi/1680
30	Game Routes	cses.fi/1681
31	Investigation	cses.fi/1202
32	Planets Queries I	cses.fi/1750
33	Planets Queries II	cses.fi/1160
34	Planets Cycles	cses.fi/1751
35	Road Reparation	cses.fi/1675
36	Road Construction	cses.fi/1676

Tree Algorithms (16)

#	Problem	Link
1	Tree Diameter	cses.fi/1131
2	Tree Distances I	cses.fi/1132
3	Tree Distances II	cses.fi/1133
4	Company Queries I	cses.fi/1687
5	Company Queries II	cses.fi/1688
6	Distance Queries	cses.fi/1135
7	Counting Paths	cses.fi/1136
8	Subtree Queries	cses.fi/1137
9	Path Queries	cses.fi/1138
10	Path Queries II	cses.fi/2134
11	Distinct Colors	cses.fi/1139
12	Finding a Centroid	cses.fi/2079
13	Fixed-Length Paths I	cses.fi/2080
14	Fixed-Length Paths II	cses.fi/2081
15	Tree Isomorphism I	cses.fi/2130
16	Tree Isomorphism II	cses.fi/2131

Mathematics (31)

#	Problem	Link
1	Josephus Queries	cses.fi/2164
2	Exponentiation	cses.fi/1095
3	Exponentiation II	cses.fi/1712
4	Counting Divisors	cses.fi/1713
5	Common Divisors	cses.fi/1081
6	Sum of Divisors	cses.fi/1082
7	Divisor Analysis	cses.fi/2182
8	Prime Multiples	cses.fi/2185
9	Counting Coprime Pairs	cses.fi/2417
10	Binomial Coefficients	cses.fi/1079
11	Creating Strings II	cses.fi/1715
12	Distributing Apples	cses.fi/1716
13	Christmas Party	cses.fi/1717
14	Fibonacci Numbers	cses.fi/1722
15	Throwing Dice	cses.fi/1096
16	Graph Paths II	cses.fi/1724
17	Dice Probability	cses.fi/1725
18	Moving Robots	cses.fi/1726
19	Candy Lottery	cses.fi/1727
20	Missing Coin Sum	cses.fi/2183

String Algorithms (17)

#	Problem	Link
1	Word Combinations	cses.fi/1731
2	String Matching	cses.fi/1753
3	Finding Borders	cses.fi/1732
4	Finding Periods	cses.fi/1733
5	Minimal Rotation	cses.fi/1110
6	Longest Palindrome	cses.fi/1111
7	Required Substring	cses.fi/1112
8	Palindrome Queries	cses.fi/2420
9	String Transform	cses.fi/2421
10	Substring Order I	cses.fi/2108
11	Substring Order II	cses.fi/2109
12	Substring Distribution	cses.fi/2110
13	Counting Patterns	cses.fi/2210
14	Pattern Positions	cses.fi/2104
15	Distinct Substrings	cses.fi/2105
16	Repeating Substring	cses.fi/2106
17	String Removal	cses.fi/2107

Additional Topics (50+)

The CSES Problem Set also covers:

Range Queries — Segment trees, Fenwick trees, Sparse tables
Geometry — Convex hull, line intersections, polygon area
Advanced Techniques — Meet in the middle, Heavy-Light decomposition
Additional Graph Algorithms — Maximum flow, min cut, matching

📁 Solutions

Solutions are available in the repo at:

DSA/questions/CSES/

Last updated: May 2026