Codeforces Round 136 (Div. 1)

5 problems from Codeforces Round 136 (Div. 1) (contest 220), difficulty 1300-2500. 3/5 solutions verified against sample I/O.

5 items

Codeforces Round 136 (Div. 1)

Div. 1 | 5 problems | 3/5 verified | Difficulty 1300-2500 | 9m 33s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Little Elephant and Problem	1300	implementation, sortings	13,116	1m 33s	✓
B	Little Elephant and Array	1800	constructive-algorithms, data-structures	12,876	1m 58s	✓
C	Little Elephant and Shifts	2100	data-structures	1,036	1m 42s
D	Little Elephant and Triangle	2500	geometry, math	314	2m 43s	✓
E	Little Elephant and Inversions	2400	data-structures, two-pointers	1,715	1m 37s

Practice › Codeforces Solutions › Codeforces Round 136 (Div. 1) ›

CF 220B - Little Elephant and Array

We are given an array of positive integers and many range queries. For each query [l, r], we look only at the subarray between those positions and count how many values x satisfy a very specific condition: Inside that subarray, the value x appears exactly x times.

Practice › Codeforces Solutions › Codeforces Round 136 (Div. 1) ›

CF 220A - Little Elephant and Problem

We are given an array that was originally sorted in non-decreasing order. At some point, either nothing happened or exactly one pair of elements may have been swapped.

Practice › Codeforces Solutions › Codeforces Round 136 (Div. 1) ›

CF 220E - Little Elephant and Inversions

We are given an array of positive integers a of length n. We need to count the number of pairs (l, r) with 1 ≤ l < r ≤ n such that if we take the element at position l and move it just before position r (shifting the elements in between right by one), the resulting array has…

Practice › Codeforces Solutions › Codeforces Round 136 (Div. 1) ›

CF 220D - Little Elephant and Triangle

We have all lattice points inside the rectangle $$0 le x le w,qquad 0 le y le h.$$ A valid answer is an ordered triple of points that forms a nondegenerate triangle whose area is a positive integer. The order matters, so every geometric triangle contributes up to $3!

Practice › Codeforces Solutions › Codeforces Round 136 (Div. 1) ›

CF 220C - Little Elephant and Shifts

We are given two permutations a and b of length n. Each permutation contains all integers from 1 to n exactly once. We are asked to compute, for every cyclic shift of b, a quantity called the distance.