89 lines
2.1 KiB
Markdown
Executable File
89 lines
2.1 KiB
Markdown
Executable File
---
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title: HackerRank - Sum of Digits of a Five Digit Number
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date: 2022-11-13 08:00:00
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categories: [Code, C]
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tags: [c, hackerrank] # TAG names should always be lowercase
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math: true
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libraries:
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- mathjax
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math: true
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---
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# Introduction
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Given a five digit integer, print the sum of its digit
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**Input**: 5 digit number, n
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**Output**: sum of 5 digit number
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## Input and Output Format
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```
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# Input
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10564
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# Output
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16
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```
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{: file="Sum Of Digits of a Five Digit Number.c" }
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$1+0+5+6+4=16$
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> This is a watered-down version of the question
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> {: .prompt-info }
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## Process
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This was my thought process while attempting this challenge.
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1. Calculate the number of digits
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1. By dividing the number by 10 and incrementing a counter in a while loop
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2. The number of digits can be found
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2. In a for loop to loop through the total number of digits (5)
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1. `sum += number % 10`
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2. `number /= 10 `
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1. This is to remove the LSB of the number for each iteration of the loop
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3. Print out the sum
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# Code
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```c
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#include <stdio.h>
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#include <string.h>
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#include <math.h>
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#include <stdlib.h>
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int main() {
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int n;
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scanf("%d", &n);
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//Complete the code to calculate the sum of the five digits on n.
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int sum = 0, divisor=10, x = n;
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if (n>=10000 && n <= 99999){
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int noOfDigits = 0;
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while (n!= 0){
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n /= 10;
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noOfDigits++;
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}
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for (int i = 0; i<= noOfDigits; i++){
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sum += x % divisor;
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x /= divisor;
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}
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printf("%d",sum);
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}
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return 0;
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}
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```
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{: file="Sum Of Digits of a Five Digit Number.c" }
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# Afterthoughts
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I initially thought that I have to increment the mod divisor by 10 everytime (i.e. $10 \times 10 \times 10$) but soon realize that it is only going to make the number bigger.
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I use the variable `n` to calculate the number of digits and used the same variable to calculate the sum, this gave me a result of 0 cuz `n` started from 0 in the loop!
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I then realize I should probably initialize `sum` to 0 cuz any uninitialized number will be given garbage, this would screw up the sum of numbers.
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