matrix.md

Matrix

• Count servers that communicate
• Count unguarded cells in the grid
• Design neighbor sum service
• Difference between ones and zeros in row and column
• Difference of number of distinct values on diagonals
• Find all groups of farmland
• Find the grid of region average
• Find the minimum area to cover all ones i
• Increment submatrices by one
• Largest submatrix with rearrangements
• Maximum matrix sum
• Maximum strictly increasing cells in a matrix
• Minimum number of flips to make binary grid palindromic i
• Minimum number of flips to make binary grid palindromic ii
• Modify the matrix
• Regions cut by slashes
• Right triangles

Geometric transformation

• Determine whether matrix can be obtained by rotation
• Equal row and column pairs
• Image overlap

Path

• Count paths with the given xor value
• Disconnect path in a binary matrix by at most one flip
• Dungeon game
• Find minimum time to reach last room i
• Find minimum time to reach last room ii
• Find the maximum number of fruits collected
• Last day where you can still cross
• Longest increasing path in a matrix
• Maximum amount of money robot can earn
• Maximum number of moves in a grid
• Minimum falling path sum
• Minimum falling path sum ii
• Minimum path sum
• Most frequent prime
• Path with maximum gold
• Paths in matrix whose sum is divisible by k
• Where will the ball fall

Prefix

• Construct product matrix
• Count submatrices with equal frequency of x and y
• Maximum difference score in a grid

Row pair processing

• Max sum of rectangle no larger than k
• Number of submatrices that sum to target

Subdivision

• Find the minimum area to cover all ones ii

Traversal

• Count negative numbers in a sorted matrix
• Diagonal traverse
• Get biggest three rhombus sums in a grid
• Minimum operations to make columns strictly increasing
• Spiral matrix iii
• Zigzag grid traversal with skip