factor out sum function

src/day_1.sh

@@ -23,9 +23,7 @@ p1() {
 
 p2() {
    read -ra cals <<< "$(cals_per_elf "$1")"
-   local result=0
-   for i in "${cals[@]: -3}"; do ((result+=i)); done
-   echo "$result"
+   utils.sum "${cals[@]: -3}"
 }
 
 p1 "$INPUT"

utils.sh

@@ -15,6 +15,15 @@ utils.qsort() {
 
   read -ra smaller_sorted <<< "$(utils.qsort "${smaller[@]}")"
   read -ra bigger_sorted <<< "$(utils.qsort "${bigger[@]}")"
+
   res=("${smaller_sorted[@]}" "$pivot" "${bigger_sorted[@]}")
+
   echo "${res[@]}"
 }
+
+utils.sum() {
+  read -ra input <<< "$@"
+  local result=0
+  for i in "${input[@]}"; do ((result+=i)); done
+  echo "$result"
+}