Educational Codeforces Round 104 (Rated for Div. 2)

Solutions for Educational Codeforces Round 104 (Rated for Div. 2) (contest 1487). 3/7 problems verified against sample I/O. Difficulty range: 800-2900.

7 items

Educational Codeforces Round 104 (Rated for Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 3/7 | Rating range: 800-2900 | Time: 20m 25s

Problem Name Rating Tags Solve Time Verified
A Arena 800 implementation, sortings 2m 10s ✓
B Cat Cycle 1200 math, number-theory 3m 2s ✗
C Minimum Ties 1500 brute-force, constructive-algorithms, dfs-and-similar 6m 5s ✗
D Pythagorean Triples 1500 binary-search, brute-force, math 2m 16s ✗
E Cheap Dinner 2000 brute-force, data-structures, graphs 2m 24s ✓
F Ones 2900 dp, greedy, shortest-paths 1m 33s ✓
G String Counting 2700 combinatorics, dp, fft 2m 55s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487G - String Counting

I can't reliably diagnose this one from the sample alone because the sample input/output pair does not identify the problem.
codeforces competitive-programming combinatorics dp fft math Jun 10, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487C - Minimum Ties

We are asked to design the results of a round-robin football tournament so that every team ends up with the same number of points. There are $n$ teams, and each pair plays exactly once.
codeforces competitive-programming brute-force constructive-algorithms dfs-and-similar graphs greedy implementation math Jun 10, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487F - Ones

We are asked to build a number equal to a given large integer using only building blocks that are themselves made entirely of digit ‘1’. Each building block is an integer like 1, 11, 111, 1111 and so on, and we are allowed to add or subtract these blocks.
codeforces competitive-programming dp greedy shortest-paths Jun 10, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487E - Cheap Dinner

We have four layers of items. The first layer contains first courses, the second layer contains second courses, the third layer contains drinks, and the fourth layer contains desserts. Every item has a cost. Between every pair of adjacent layers, some combinations are forbidden.
codeforces competitive-programming brute-force data-structures graphs greedy implementation sortings two-pointers Jun 10, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487D - Pythagorean Triples

We are looking for integer triples $(a, b, c)$ such that $1 le a le b le c le n$. Two conditions must hold at the same time.
codeforces competitive-programming binary-search brute-force math number-theory Jun 10, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487B - Cat Cycle

I can't reliably diagnose this one from the sample alone because the sample input/output pair does not identify the problem.
codeforces competitive-programming math number-theory Jun 10, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 104 (Rated for Div. 2) ›

CF 1487A - Arena

We are given a collection of heroes, each with an initial strength or level. They fight pairwise, and whenever two heroes with different levels meet, the stronger one wins and grows stronger. If their levels are equal, the fight is a draw and nobody gains anything.
codeforces competitive-programming implementation sortings Jun 10, 2026