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Daily Challenge #184 - Form the Minimum

dev.to staff on February 11, 2020

Setup Given an array of integers, implement a function that will return the lowest possible number that can be formed from these digits....

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Craig McIlwrath • Feb 11 '20

Haskell. Also works for empty lists, returns 0.

import Data.List (nub, sort)
import Data.Maybe (fromMaybe) 
import Text.Read (readMaybe) 

minVal :: [Int] -> Int
minVal = fromMaybe 0 . readMaybe . concatMap show . sort . nub

@nobody • Feb 11 '20

this is why Haskell scares me :o
that looks like Overlord Wizardry compared
to Clojure

Valts Liepiņš • Feb 11 '20 • Edited

Ruby:

def minValue arr
    set = arr.uniq.sort
    set[0..1] = set[0..1].rotate if set[0] == 0 # Edge case for sets with 0
    set.join.to_i
end

Edit: Fixed the 0 edge case. Instead of adding 0 to the end of the number, put it in the 2. position.

Simon Landry • Feb 12 '20

Wouldn't rotating the array bring the biggest number at the front?

I think swapping the 1st and 2nd number would be ideal.

Also is having a leading zero really against the rules?

Valts Liepiņš • Feb 12 '20

Yeah, swapping seems to be better, would keep the large digits in the lesser valuable positions.

I interpreted the rules this way, because it didn't seem right to lose a digit in the resulting number. That would be like assuming input set [1,2,0] as equivelent to [1,2].

Viktor • Feb 12 '20

My try to solve this challenge :)

In my solution I don't include 0 in end result.

var minValue = arr => parseInt(arr.sort().map((e,i,a) => {if( e != a[i+1])return e;}).filter(x=>x).toString().replace(/,/g, ""));

matej • Feb 13 '20

Java

public String minValue(int[] ints) {
   return Arrays.stream(ints)
      //.filter(i -> i > 0) //does not include zeroes
      .distinct()
      .sorted()
      .mapToObj(i -> String.valueOf(i))
      .collect(Collectors.joining());
}

emadsaber • Feb 12 '20

Javascript

function getMinimum(arr){
let sorted = arr.sort();
let distinct = '';

sorted.forEach(function(element){
if(distinct.indexOf(element) < 0){
distinct = ${distinct}${element};
}
});

console.log(parseInt(distinct));
return parseInt(distinct);
}

Vidit Sarkar • Feb 11 '20 • Edited

Here is my C++ code

vector<int> minValueHelper(vector<int> v){
    set<int> s;
    bool presentZero = false;
    for(int i : v){
        if(i==0)
            presentZero = true;
        s.insert(i);
    }
    if(presentZero){
        // because 0 cannot be in front of any number
        // minValue({1, 1, 7, 0}) should not return 017 but should return 107
        vector<int> v(s.begin(),s.end());

        // if only zero is given in vector return zero
        // else swaping
        if(v.size() > 1)
            swap(v[0],v[1]);
        return v;
    }
    return vector<int>(s.begin(),s.end());
}

int minValue(vector<int> v){
    vector<int> minVector = minValueHelper(v);
    string s = "";
    for(int i : minVector)
        s += to_string(i);
    return stoi(s);
}

divyansh-pratap • Feb 11 '20 • Edited

this is solution in c . I have first sorted the array then solved it using simple logics . suggestions are welcome .

include

int sort(int A[] , int n );
int min(int A[] , int n);
int main()
{
int A[30];
int a , i , s;
printf("enter the number of elements you want to enter");
scanf("%d" ,&a);

for(i=0;i<a;i++)
{
    printf("enter the %dth element" , i+1);
    scanf("%d" , &A[i]);
}
s = min(A , a);
printf("/n %d" , s);

}
int sort(int A[] , int n )
{
int i;
int temp , j;
for(i=0;i<n;i++)
{
for(j=i+1;j<n;j++)
{
if(A[j]<A[i])
{
temp=A[i];
A[i]=A[j];
A[j]=temp;
}
}
}
}

int min(int A[] ,int n)
{
int s , j=0 , k , i , l=1;

  sort(A , n);
  s=A[0];
  for(i=1;i<n;i++)
  {

    j=A[i];

    for(k=0;k<i;k++)
    {
        if(A[i]==A[k])
        {
         l=0;
          }
      }
    if(l==1)
    {
        s=s*10 + j;
      }

     l=1 ;

  }

  return s;

}

Matt Ellen-Tsivintzeli • Feb 12 '20 • Edited

const minValue = ns => parseInt([...(new Set(ns))].sort().join(''));

George WL • Feb 13 '20 • Edited

Even works for [7,0,2], neat

SavagePixie • Feb 11 '20 • Edited

JavaScript

const formMin = arr => +Array
  .from(new Set(arr))
  .sort((a, b) => a - b)
  .join('')

Rohit Prasad • Feb 14 '20

Python

var = input("Enter the numbers: ")
var = list(set(var))
var.sort()
var = ''.join(var)
print(var)