Practice Problems

Problem of the Day: Integer Square Root — keep your streak alive!

Practice Problems — combinatorics

#ProblemTopicsDifficulty
167 Counting All Subsets math combinatorics 1100
448 All the Rectangles math combinatorics 1200
344 A Row of Pascal's Triangle math combinatorics 1300
903 Row Coloring, 3 Colors combinatorics 1300
904 Row Coloring, 4 Colors combinatorics 1300
905 Row Coloring, 5 Colors combinatorics 1300
162 Routes Across a Grid math combinatorics 1400
163 Catalan Number math combinatorics 1400
636 Painting the Fence math combinatorics 1400
637 Counting Dice Rolls dp combinatorics 1400
161 Binomial Coefficient math combinatorics 1500
166 Distributing Identical Coins math combinatorics 1500
667 Cayley's Forest combinatorics graphs 1500
164 Count the Derangements math combinatorics 1600
455 Two Peaceful Knights math combinatorics 1600
743 Binary Strings Avoiding 111 combinatorics matrix-exponentiation 1600
902 Domino Tilings of 2xN combinatorics matrix-exponentiation 1700
584 Partitions into K Groups combinatorics 1800
668 Ways to Partition a Set dp combinatorics 1800
744 Walks on a Triangle combinatorics matrix-exponentiation 1800
745 Strings with an Even Number of Zeros combinatorics matrix-exponentiation 1800
741 Tiling 2xN with Dominoes and L-Trominoes combinatorics matrix-exponentiation 1900
826 Strings Avoiding 21 combinatorics kmp matrix-exponentiation 1900
827 Strings Avoiding 20 combinatorics kmp matrix-exponentiation 1900
859 Numbers with K Set Bits combinatorics digit-dp 1900
669 Onto Functions combinatorics 2000
742 Ternary Strings Avoiding 22 combinatorics matrix-exponentiation 2000
921 No Three in a Row dp combinatorics matrix-exponentiation 2000
582 Binomial Modulo Small Prime combinatorics number-theory 2100
761 Binary Strings Avoiding 101 combinatorics kmp matrix-exponentiation 2100
762 Binary Strings Avoiding 000 combinatorics kmp matrix-exponentiation 2100
763 Binary Strings Avoiding 0011 combinatorics kmp matrix-exponentiation 2100
764 Ternary Strings Avoiding 012 combinatorics kmp matrix-exponentiation 2100
765 Ternary Strings Avoiding 00 combinatorics kmp matrix-exponentiation 2100
766 Binary Strings Avoiding 1001 combinatorics kmp matrix-exponentiation 2100
767 Binary Strings Avoiding 11 combinatorics kmp matrix-exponentiation 2100
768 Ternary Strings Avoiding 11 combinatorics kmp matrix-exponentiation 2100
790 Avoid 11 and 000 combinatorics aho-corasick matrix-exponentiation 2100
793 Avoid 110 and 011 combinatorics aho-corasick matrix-exponentiation 2100
794 Avoid 01 and 12 combinatorics aho-corasick matrix-exponentiation 2100
818 Strings Avoiding 010 combinatorics kmp matrix-exponentiation 2100
819 Strings Avoiding 0110 combinatorics kmp matrix-exponentiation 2100
820 Strings Avoiding 1010 combinatorics kmp matrix-exponentiation 2100
821 Strings Avoiding 0101 combinatorics kmp matrix-exponentiation 2100
822 Strings Avoiding 1100 combinatorics kmp matrix-exponentiation 2100
823 Strings Avoiding 0010 combinatorics kmp matrix-exponentiation 2100
824 Strings Avoiding 1110 combinatorics kmp matrix-exponentiation 2100
825 Strings Avoiding 0001 combinatorics kmp matrix-exponentiation 2100
828 Strings Avoiding 010 combinatorics kmp matrix-exponentiation 2100
829 Strings Avoiding 121 combinatorics kmp matrix-exponentiation 2100