Alternate Digits sum

johnsfine · 09-14-2012, 10:34 AM

Quote:

Originally Posted by Balvinder87

It is not giving the actual values not even for odd,even positions

We understand that it is not working and why it is not working. I added some detail to my earlier post (after pressing send the first time), so if you read my post too soon, please reread it. Otherwise, you answered too fast to have thought about the things I suggested you think about.

kotanjan · 09-24-2012, 03:05 AM

konsolebox · 09-24-2012, 04:57 AM

Quite interesting. This is doable in C of course, but just as a proof on concept, we could do it in bash as well:

Code:

#!/bin/bash

read -p "Enter an integer: " INT

shopt -s extglob

if [[ $INT != +([[:digit:]]) ]]; then
	echo "That's not an acceptable integer."
	exit 1
fi

SUMS=()

for (( I = ${#INT}; I; --I )); do
	D=${INT:I - 1:1}
	if (( I % 2 )); then
		(( SUMS[1] += D ))
	else
		(( SUMS[2] += D ))
	fi
	if (( (I % 3) == 0 )); then
		(( SUMS[3] += D ))
	fi
done

echo "${SUMS[*]}"

johnsfine · 09-24-2012, 07:26 AM

Quote:

Originally Posted by kotanjan

function AddAlterbnateDigits(num)

1) When posting code, please use CODE tags. Reading code the way you just posted it is difficult. This time I didn't bother. Many experts here will never take the extra effort to read code that is posted badly.

2) When answering homework questions, please do not do the homework. There are lots of programmers in this forum for whom these homework assignments are trivial, so no one will be impressed that someone not taking the class can do the homework.
It is usually harder to give helpful information that enables the OP to do his own homework than it is to provide a solution the OP could copy. But that is the goal here.

danielbmartin · 09-25-2012, 07:49 PM

Quote:

Originally Posted by Balvinder87

For eg: given an integer 158176
your program should add
- 1,8,7 which are in the position 0,2,4 of the integer AND
- 5,1,6 which are in position 1,3,5 of the integer AND
- 8,6 which are in every 3rd place in the integer.
So the answer will be 1+8+7=16, 5+1+6=12 and 8+6=14. The output will be 16,12,14

I'm learning awk, so I coded this ...

Code:

echo 158176  \
|awk -F "" '{for (i=1;i<=NF;i++) 
  (1==i%2)?
    s1=s1+$i:
    s2=s2+$i}
  END {print s1, s2}'

... which produces this ...

Code:

16 12

Okay, that's two of the three desired results. Then I tried to extend the code to generate all three numbers ...

Code:

echo 158176  \
|awk -F "" '{for (i=1;i<=NF;i++) 
  (1==i%2)?
    s1=s1+$i:
    s2=s2+$i 
  (2==i%3)?
    s3=s3+$1} 
  END {print s1, s2; s3}

... and get this ...

Code:

awk: cmd. line:5:     s3=s3+$1} 
awk: cmd. line:5:             ^ syntax error

awk experts, please advise.

Daniel B. Martin

konsolebox · 09-25-2012, 08:06 PM

daniel: Why don't you just use if blocks/statements?

konsolebox · 09-25-2012, 08:38 PM

My version in awk. You might want to refer from this.

Code:

#!/usr/bin/env gawk -f

BEGIN {
	printf "Enter an integer: ";

	getline number < "/dev/stdin"

	if (number !~ /^[[:digit:]]+$/) {
		printf "That's not an acceptable integer.\n"
		exit 1
	}

	for (i = length(number); i; --i) {
		d = int(substr(number, i, 1))
		if (i % 2) {
			sum1 = sum1 + d
		}
		else {
			sum2 = sum2 + d
		}
		if ((i % 3) == 0) {
			sum3 = sum3 + d
		}
	}

	printf "%d %d %d\n", sum1, sum2, sum3

	exit(0)
}