Get Sum Target Index Thing

get-sum-target-index-thing.sh

# Given an array of integers, return indices of the two numbers
# such that they add up to a specific target.

# You may assume that each input would have exactly one solution,
# and you may not use the same element twice.

# Example: [1,2,3,4], 7 -> 2,3

# chmod +x get-sum-target-index-thing.sh && ./get-sum-target-index-thing.sh 7 1 2 3 4
if [ -z  "$1" ]; then
  echo "Must provide a target"
  exit 1
fi
TARGET="$1"

echo "Target: $TARGET"
STACK_FILENAME="stack.txt"
rm -rf "$STACK_FILENAME"
touch "$STACK_FILENAME"

for value in "$@"; do
  if [ "$value" != "$TARGET" ]; then
    echo "$value" >> "$STACK_FILENAME"
  fi
done

SUM_CHECK=0
TOTAL=$(cat $STACK_FILENAME | wc -l)
for x in $(cat $STACK_FILENAME); do
  INDEX=$(cat $STACK_FILENAME | grep -n ${x} - | awk -F: '{print $1}')
  NEXT=$(expr $TOTAL - $INDEX)
  for y in $(cat $STACK_FILENAME | tail -${NEXT}); do
      YINDEX=$(cat $STACK_FILENAME | grep -n ${y} - | awk -F: '{print $1}')
      SUM_CHECK=$((x + y))
      if [ "$SUM_CHECK" -eq "$TARGET" ]; then
        echo "This is the way: ($INDEX,$YINDEX)"
        exit 0
      fi
  done
done