Removing Digits from a Number

Removing Digits from a Number

Try this:

var num = 1234

var first = num/100
var last = num%100

The playground's output is what you need.

How can I remove a certain number of digits in a number so the number obtained is minimal?

The basic idea is that if you can only remove one digit, you want to remove the first digit (starting with the most significant digit) that is followed by a smaller digit.

For example, if your number is 123432, you want to remove the 4 (since it is followed by a 3), resulting in 12332.

You then repeat this process for as many digits as you want to remove:

char *num = "69469813";
char *buf = malloc(strlen(num)+1);
size_t to_remove = 4;

while (to_remove --> 0) {
    char *src = num;
    char *dst = buf;

    while (*src < *(src+1)) { *dst++ = *src++; } // Advance until the next digit is less than the current digit
    src++;                                       // Skip it
    while (*dst++ = *src++);                     // Copy the rest

    strcpy(num, buf);
}
printf("%s\n", num); // Prints 4613

How to delete specific digit from integer?

This does not require arrays nor loops:

int n = 1237534;

String newNum = String.valueOf(n);
char c = '3';
StringBuilder sb1 = new StringBuilder( newNum );
StringBuilder sb2 = new StringBuilder( newNum );

int newGuess1 = Integer.parseInt(sb1.deleteCharAt(newNum.indexOf(c)).toString());
int newGuess2 = Integer.parseInt(sb2.deleteCharAt(newNum.indexOf(c, newNum.indexOf(c)+1)).toString());

System.out.println( newGuess1 > newGuess2 ? newGuess1: newGuess2 );

Removing a digit from a number in c++

Here is what you looking for:

#include <bits/stdc++.h>
using namespace std;

int deleteNumber(int num, int n)
{
  
    // Get the length of digits
    int d = log10(num) + 1;
  
    // Declare a variable
    // to form the reverse resultant number
    int rev_new_num = 0;
  
    // Loop with the number
    for (int i = 0; num != 0; i++) {
  
        int digit = num % 10;
        num = num / 10;
  
        // skip to add if the number is what we need to remove
        if (digit == n) {
            continue;
        }
        else {
            rev_new_num = (rev_new_num * 10) + digit;
        }
    }
  
    // Declare a resultant number var
    int new_num = 0;
  
    // Loop with the number
    for (int i = 0; rev_new_num != 0; i++) {
  
        new_num = (new_num * 10)
                  + (rev_new_num % 10);
        rev_new_num = rev_new_num / 10;
    }
  
    // Return the resultant number
    return new_num;
}
  
  
// Driver code
int main()
{
  
    int num = 123432111;
    
    // the digit to be deleted
    int n = 1;
  
    // Remove the specified digit from starting
    cout << deleteNumber(num, n) << endl;
    return 0;
}

do while version of it would be:

// C++ implementation of above approach
#include <bits/stdc++.h>
using namespace std;

int deleteNumber(int num, int n)
{
  
    // Get the length of digits
    int d = log10(num) + 1;
  
    // Declare a variable
    // to form the reverse resultant number
    int rev_new_num = 0;
  
    // Loop with the number
    do {
        int digit = num % 10;
        // skip to add if the number is what we need to remove
        if (digit == n) {
            continue;
        }
        else {
            rev_new_num = (rev_new_num * 10) + digit;
        }
        
    } while(num = num / 10);
  
    // Declare a resultant number var
    int new_num = 0;
  
    // Loop with the number
    for (int i = 0; rev_new_num != 0; i++) {
  
        new_num = (new_num * 10)
                  + (rev_new_num % 10);
        rev_new_num = rev_new_num / 10;
    }
  
    // Return the resultant number
    return new_num;
}
  
  
// Driver code
int main()
{
  
    int num = 123432111;
    
    // the digit to be deleted
    int n = 3;
  
    // Remove the specified digit from starting
    cout << deleteNumber(num, n) << endl;
    return 0;
}

C++ removing a custom digit from a number

Her is a function which solves your problem

int removeDecimal( int number, int digitNo )
{
    int result = number;
    int decimal = (int)pow( 10, digitNo ); // caluclate 10.0e<digitNo>

    // int decimal = 1;
    // for ( int i = 0; i < digitNo; i ++ ) decimal *= 10; // alternative to pow( 10, digitNo )

    int div = number / decimal;                      
    if ( div > 0 )                         // test if number is grater than 10.0e<digitNo>
    {
        int rest = number % decimal;       // calcualte right digits
        result = div / 10;                 // calcualte left digits
        result *= 10 * decimal;            // shift left digits to the left
        result += rest;                    // add right digits
    }
    return result;
}

How to remove a particular digit from an integer using javascript

Try this :

// Input
let number = 789012345;

// Convert number into a string
let numberStr = number.toString();

// Replace the 0 with empty string
const res = numberStr.replace(numberStr[3], '');

// Convert string into a number.
console.log(Number(res));

print $ ((((i * 5) + 6) * 4 + 9) * 5) / 100 - 1

print $ ((((i * 5) + 6) * 4 + 9) * 5) `div` 100 - 1

print $ (div ((((i * 5) + 6) * 4 + 9) * 5) 100) - 1

main = getLine >>= print

removeDigits :: [Int] -> Int -> Int
removeDigits indices x = read . reverse . filterIndices indices . reverse . show $ x

filterIndices :: [Int] -> [a] -> [a]
filterIndices inds elems = map snd . filter ((`notElem` inds) . fst) . zip [1..] $ elems

transform = (subtract 1) . (`quot` 100) . (*5) . (+9) . (*4) . (+6) . (*5)

System.out.print("Enter a digit you want to remove: ");
int a;
a = input.nextInt();
String newString = number.substring(0, a - 1) + number.substring(a);
int new_number = Integer.parseInt(newString);