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Count inversion pairs in a matrix
January 7, 2017

Given a matrix A of size NxN, we need to find the number of inversion pairs in it. Inversion count in a matrix is defined… Read More »

January 7, 2017

Given a matrix A of size NxN, we need to find the number of inversion pairs in it. Inversion count in a matrix is defined… Read More »

October 10, 2016

Let us consider the below problem statement and think of different solutions for it. Given a set S of elements such that the elements are… Read More »

October 6, 2016

Given an array arr[0..n-1]. The following operations need to be performed. update(l, r, val) : Add ‘val’ to all the elements in the array from… Read More »

October 4, 2016

ACM ICPC(Association for Computing Machinery – International Collegiate Programming Contest) is a world-wide annual multi-tiered programming contest being organized for over thirteen years. The contest… Read More »

September 30, 2016

August 9, 2016

Prerequisites: BIT Given ‘n’ line segments, each of them is either horizontal or vertical, find the maximum number of triangles(including triangles with zero area) that… Read More »

July 24, 2016

Prerequisites : BIT, DFS Given a rooted tree T, with ‘n’ nodes, each node has a color denoted by the array color[](color[i] denotes the color… Read More »

July 16, 2016

Prerequisite – Fenwick Tree We know that to answer range sum queries on a 1-D array efficiently, binary indexed tree (or Fenwick Tree) is the… Read More »

July 15, 2016

Pre-requisite : BIT(Binary Indexed Tree or Fenwick Tree), 2D BIT Given a 2D plane, respond to Q queries, each of the following type: Insert x… Read More »

December 21, 2015

Given an array arr[] of size n. Three elements arr[i], arr[j] and arr[k] form an inversion of size 3 if a[i] > a[j] >a[k] and… Read More »

December 18, 2015

Inversion Count for an array indicates – how far (or close) the array is from being sorted. If array is already sorted then inversion count… Read More »

December 16, 2015

In this post “Important top 10 algorithms and data structures for competitive coding “. Topics : Graph algorithms Dynamic programming Searching and Sorting: Number theory… Read More »

December 11, 2014

Let us consider the following problem to understand Binary Indexed Tree.