I am trying to run the below code using for loop but i am getting syntax error. Please help.
Input Format: The first line of the input contains an integer N, indicating the number of integers. The next line contains N space-separated integers that form the array A.
read n
sum=0
for (( i=1; i<= "$n" ; i++ ))
do
read val
sum ^= $val;
done
echo $sum
Below is the error message
solution.sh: line 4: ((: i<= 1
: syntax error: invalid arithmetic operator (error token is "
")
The printf "%s" "$n" | hexdump -C shows that the CR is contained in the input rather than in the script file, so running dos2unix on the script won't help anyway. A simple means to get rid of it is setting IFS=$'\r'.
Then, read val in a loop is unfit to read space-separated integers, since read reads a whole line at a time. But for the task of bitwise exclusive ORing those N space-separated integers we don't need an explicit loop - we can just replace all spaces with the desired operator and evaluate the result.
#!/bin/bash
IFS=$'\r'
read n
read a
((sum = ${a// /^}))
echo $sum
This will work. However you should insert some helper messages inside:
#!/bin/bash
read n
sum=0
for (( i=1; i<=n; i++ ))
do
read val
((sum^=val))
done
echo $sum
^= is a valid bash arithmetic context assignment operator (though not with the spaces obviously) but this doesn't solve the actual problem the poster is having.
dos2unix solution.sh and the rerunning my example. Etan Reisner: thanks for the note (corrected).
$is valid in that context though (despite being unnecessary most of the time) and is not the error.printf "%s" "$n" | hexdump -Cbefore the while loop; what output does it produce?0dis a carriage return. Your script file contains DOS newlines as suggested by Etan. Rundos2unixon your script, or use your favorite text editor to save the file with Unix newlines.