← All sheets
Basics of Number Theory
Build a foundation in number theory — 100 CodeForces problems tagged number theory, laddered from 800 up to 1400 as the ideas get sharper.
100 problems33 rated 80016 rated 90019 rated 100012 rated 11006 rated 12008 rated 13006 rated 1400
| # | Problem | Rating | Status | Links |
|---|---|---|---|---|
| 001 | Game with Integers1899A | 800 | ||
| 002 | Again Twenty Five!630A | 800 | ||
| 003 | Design Tutorial: Learn from Math472A | 800 | ||
| 004 | Maximum GCD1370A | 800 | ||
| 005 | Bachgold Problem749A | 800 | ||
| 006 | Maximum Multiple Sum1985B | 800 | ||
| 007 | United We Stand1859A | 800 | ||
| 008 | LCM Problem1389A | 800 | ||
| 009 | Ordinary Numbers1520B | 800 | ||
| 010 | Forbidden Integer1845A | 800 | ||
| 011 | EhAb AnD gCd1325A | 800 | ||
| 012 | Maximize?1968A | 800 | ||
| 013 | I'm bored with life822A | 800 | ||
| 014 | Sieve of Erato67henes2195A | 800 | ||
| 015 | Turtle Math: Fast Three Task1933B | 800 | ||
| 016 | Gregor and Cryptography1549A | 800 | ||
| 017 | Serval and Mocha's Array1789A | 800 | ||
| 018 | Digits Sum1553A | 800 | ||
| 019 | Minimal Coprime2063A | 800 | ||
| 020 | Greatest Convex1768A | 800 | ||
| 021 | Kamilka and the Sheep2092A | 800 | ||
| 022 | 20231916A | 800 | ||
| 023 | The Play Never Ends2071A | 800 | ||
| 024 | Two Regular Polygons1312A | 800 | ||
| 025 | Strange Functions1455A | 800 | ||
| 026 | Potion-making1525A | 800 | ||
| 027 | Carnival Wheel2180A | 800 | ||
| 028 | Find Minimum Operations2020A | 800 | ||
| 029 | Captain Flint and Crew Recruitment1388A | 800 | ||
| 030 | Perfectly Imperfect Array1514A | 800 | ||
| 031 | Dora's Set2007A | 800 | ||
| 032 | GCD Arrays1629B | 800 | ||
| 033 | Circuit2032A | 800 | ||
| 034 | Odd Divisor1475A | 900 | ||
| 035 | Ilya and Bank Account313A | 900 | ||
| 036 | Longest Divisors Interval1855B | 900 | ||
| 037 | Almost Prime26A | 900 | ||
| 038 | Exciting Bets1543A | 900 | ||
| 039 | AvtoBus1679A | 900 | ||
| 040 | Permutation Swap1828B | 900 | ||
| 041 | Strange Partition1471A | 900 | ||
| 042 | Array Reodering1535B | 900 | ||
| 043 | Hexadecimal's theorem199A | 900 | ||
| 044 | Prime Subtraction1238A | 900 | ||
| 045 | Left and Down2125B | 900 | ||
| 046 | Yet Another Tetris Problem1324A | 900 | ||
| 047 | GCD Problem1617B | 900 | ||
| 048 | Fun Permutation2137B | 900 | ||
| 049 | Fireworks1945B | 900 | ||
| 050 | Lucky Division122A | 1000 | ||
| 051 | Arpa’s hard exam and Mehrdad’s naive cheat742A | 1000 | ||
| 052 | Multiplication Table577A | 1000 | ||
| 053 | Nastia and Nearly Good Numbers1521A | 1000 | ||
| 054 | Different Divisors1474B | 1000 | ||
| 055 | Mahmoud and a Triangle766B | 1000 | ||
| 056 | String LCM1473B | 1000 | ||
| 057 | Add and Divide1485A | 1000 | ||
| 058 | Minimum LCM1765M | 1000 | ||
| 059 | Bad Ugly Numbers1326A | 1000 | ||
| 060 | Two Divisors1916B | 1000 | ||
| 061 | Fair Numbers1411B | 1000 | ||
| 062 | Simple Repetition2093C | 1000 | ||
| 063 | Yet Another Array Problem2167D | 1000 | ||
| 064 | Assembly via Remainders1968C | 1000 | ||
| 065 | Minimize Equal Sum Subarrays1998B | 1000 | ||
| 066 | Phoenix and Puzzle1515B | 1000 | ||
| 067 | Superultra's Favorite Permutation2037C | 1000 | ||
| 068 | Yet Another Permutation Problem1858C | 1000 | ||
| 069 | Coprime1742D | 1100 | ||
| 070 | 250 Thousand Tons of TNT1899B | 1100 | ||
| 071 | Perfect Number919B | 1100 | ||
| 072 | Lunatic Never Content1826B | 1100 | ||
| 073 | GCD Partition1780B | 1100 | ||
| 074 | Product of Binary Decimals1950D | 1100 | ||
| 075 | Non-coprime Split1872C | 1100 | ||
| 076 | Turtle Fingers: Count the Values of k1933C | 1100 | ||
| 077 | Divisors of Two Integers1108B | 1100 | ||
| 078 | GCD Compression1370B | 1100 | ||
| 079 | Counterexample 483A | 1100 | ||
| 080 | GCD Length1511B | 1100 | ||
| 081 | Pleasant Pairs1541B | 1200 | ||
| 082 | Make Almost Equal With Mod1909B | 1200 | ||
| 083 | XXXXX1364A | 1200 | ||
| 084 | Cat Cycle1487B | 1200 | ||
| 085 | Sherlock and his girlfriend776B | 1200 | ||
| 086 | Yet Another Array Restoration1409C | 1200 | ||
| 087 | T-primes230B | 1300 | ||
| 088 | Product of Three Numbers1294C | 1300 | ||
| 089 | Buying Shovels1360D | 1300 | ||
| 090 | Omkar and Last Class of Math1372B | 1300 | ||
| 091 | Divisible Pairs1931D | 1300 | ||
| 092 | Divide and Equalize1881D | 1300 | ||
| 093 | Mere Array1401C | 1300 | ||
| 094 | We Were Both Children1850F | 1300 | ||
| 095 | I Hate 11111526B | 1400 | ||
| 096 | Orac and Models1350B | 1400 | ||
| 097 | Mashmokh and ACM414B | 1400 | ||
| 098 | Fadi and LCM1285C | 1400 | ||
| 099 | Number Game1370C | 1400 | ||
| 100 | k-th divisor762A | 1400 |
“Open in app” uses the cpally:// protocol and opens the problem directly in CP Ally IDE.