FastPrepDense Matrix Multiplication

Dense Matrix Multiplication

Amazon logoAmazon● MediumFULLTIMEPHONE SCREEN

Problem statement

Given rectangular integer matrices left of shape m x k and right of shape k x n, return their m x n matrix product.

Each output entry is the dot product of one left row and one right column: result[i][j] = sum(left[i][t] * right[t][j]) for 0 <= t < k.

The problem statement continues
Pro

Examples

Example 1

left = [[1,2],[3,4]]right = [[5,6],[7,8]]return = [[19,22],[43,50]]

Two-by-two dot products.

FastPrep Pro
Reported in 1 Amazon interview this week

Unlock this recently reported problem

FastPrep Pro gives you full access to interview problems reported within the last week.

  • Full problem statement and constraints
  • 2 more worked examples, explained
  • Guided hints and editorial
  • Run your code on real test cases
$8.25/month

$99 billed yearly — or $19 month-to-month. Cancel anytime.

Free plan — 2 of 2 free unlocks used this week
See Amazon hiring insights
CodePython 3
Run and Submit unlock with Pro
FastPrep Pro
Reported in 1 Amazon interview this week

Unlock this recently reported problem

FastPrep Pro gives you full access to interview problems reported within the last week.

  • Full problem statement and constraints
  • 2 more worked examples, explained
  • Guided hints and editorial
  • Run your code on real test cases
$8.25/month

$99 billed yearly — or $19 month-to-month. Cancel anytime.

Free plan — 2 of 2 free unlocks used this week