Problem 42636. Big Integer Multiplication

Created by LY Cao

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Implement big integer multiply.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Input:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>A, B : N-by-M Matrix, each row represents a positive decimal integer.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Output:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>C : N-by-P Matrix, each row represents the decimal integer A*B.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Example 1:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[a = [1 2 3;0 5 6];\nb = [5 6;9 0];\nc = BigIntMult(a,b)\nc =\n   6     8     8     8\n   5     0     4     0]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>123*56=6888 (c(1,:)), 56*90=5040 (c(2,:))</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Example 2 (singleton expansion):</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[a = [1 2 3;0 5 6];\nb = [5 7];\nc = BigIntMult(a,b)\nc =\n   7     0     1     1\n   3     1     9     2]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>123*57=7011 (c(1,:)), 56*57=3192 (c(2,:))</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Note:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>1.you don't need to remove the leading zeroes.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>2.your score will depend on your solution performance.</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Solve

Solution Stats

128 Solutions
7 Solvers

Last Solution submitted on Jan 03, 2023

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

James on 29 Sep 2015

Is the 123 in a(1,:) being multiplied by the 056 in a(2,:) or the 56 in b(1,:)?

Tim on 29 Sep 2015

The 56 in b(1,:).

Peng Liu on 29 Sep 2015

The latter.

LY Cao on 29 Sep 2015

The 56 in b(1,:),Thank you for pointing out the confusion James.I'll edit it.

Dyuman Joshi on 15 Aug 2022

Note that in Test case #3, b is a row vector (1xm) as opposed to a matrix (nxm) as mentioned in the problem description.

Also, Test case #1, set for manually assigning score based on performance, is no longer valid and any solution submitted now on (even if correct) won't be accepted.
I even ran Tim's solution to verify that the problem was with the test case and not the solutions submitted.

Last accepted solution is J.R.! Menzinger's on 6 Aug 2021.

Solution Comments

Show comments

Problem Recent Solvers7

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 42636. Big Integer Multiplication

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers7

Suggested Problems

More from this Author8

Problem Tags

Community Treasure Hunt

Problem 42636. Big Integer Multiplication

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers7

Suggested Problems

More from this Author8

Problem Tags

Community Treasure Hunt

Players