Posted on May 13, 2020

Daily Challenge #242 - Expressions Matter

Given three integers a ,b ,c, return the largest number obtained after inserting the following operators and brackets: +, *, () In other words , try every combination of a,b,c with [*,+,()] , and return the highest number.

Here's an example:

1 * (2 + 3) = 5 1 * 2 * 3 = 6 1 + 2 * 3 = 7 (1 + 2) * 3 = 9 <-- So the maximum value that you can obtain is 9.

Tests

expression_matter(5, 1, 3)
expression_matter(3, 5, 7)
expression_matter(5, 6, 1)
expression_matter(1, 6, 1)
expression_matter(2, 6, 1)

Good luck!

This challenge comes from MrZizoScream on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

Want to propose a challenge idea for a future post? Email yo+challenge@dev.to with your suggestions!

Top comments (7)

Shohan • May 14 '20 • Edited

If one of the numbers is 1, and if the next bigger number is y and largest number is z, ans will be z * (1 + y), else ans will be x * y * z

def expressions_matter(a, b, c): x = sort([a, b, c]) if x[0] == 1: return (1 + x[1]) * x[2] return x[0] * x[1] * x[2]

Vidit Sarkar • May 13 '20

Here is a Python solution,

expression_formats = [ '{}+{}+{}', '{}*{}*{}', '{}+{}*{}', '{}*{}+{}', '({}+{})*{}', '{}*({}+{})' ] def expression_matter(a,b,c): return max(eval(s.format(a,b,c)) for s in expression_formats)

Output,

print(expression_matter(1, 2, 3)) # output -> 9 print(expression_matter(5, 1, 3)) # output -> 20 print(expression_matter(3, 5, 7)) # output -> 105 print(expression_matter(5, 6, 1)) # output -> 35 print(expression_matter(1, 6, 1)) # output -> 8 print(expression_matter(2, 6, 1)) # output -> 14

peter279k • Jun 20 '20

Here is the simple solution for PHP:

function expressionMatter($a, $b, $c) { $possible_ans = [ $a * $b * $c, $a + $b + $c, ($a + $b) * $c, $a + $b * $c, $a * $b + $c, $a * ($b + $c), ]; return max($possible_ans); }

Davide Santangelo • May 13 '20 • Edited

maybe not the most elegant, but it work!

def expression_matter(a,b,c) sum = [a,b,c].sum tmp = [a,b,c].inject('*') sum = tmp if sum < tmp tmp = (a + b) * c sum = tmp if sum < tmp tmp = a + (b * c) sum = tmp if sum < tmp tmp = a * (b + c) sum = tmp if sum < tmp tmp = (a + c ) * b sum = tmp if sum < tmp sum end

pry(main)> expression_matter(5, 1, 3) => 20 pry(main)> expression_matter(3, 5, 7) => 105 pry(main)> expression_matter(5, 6, 1) => 36 pry(main)> expression_matter(1, 6, 1) => 12 pry(main)> expression_matter(2, 6, 1) => 18

Shaurya • May 13 '20 • Edited

My solution using Rust .
Playground

fn expressions_matter(a: u32, b: u32, c: u32) -> u32 { let mut all_calculations = [ a + b + c, a * b * c, a + b * c, (a + b) * c, a * b + c, a * (b + c), ]; all_calculations.sort(); all_calculations[5] }

K.V.Harish • May 16 '20

In javascript

const expression_matter=(t,a,e)=>Math.max(t+a+e,t*a*e,t+a*e,(t+a)*e,t*a+e,t*(a+e));

Shohan • May 15 '20

Hmm yes, but looking at the examplea given, I assumed a, b and c would be positive