Data commit

Task/Gapful-numbers/UNIX-Shell/gapful-numbers.sh

@@ -0,0 +1,43 @@
+first-digit() {
+  printf '%s\n' "${1:0:1}"
+}
+
+last-digit() {
+  printf '%s\n' $(( $1 % 10 ))
+}
+
+bookend-number() {
+  printf '%s%s\n' "$(first-digit "$@")" "$(last-digit "$@")"
+}
+
+is-gapful() {
+  (( $1 >= 100 && $1 % $(bookend-number "$1") == 0 ))
+}
+
+gapfuls-in-range() {
+  local gapfuls=()
+  local -i i found
+  for (( i=$1, found=0; found < $2; ++i )); do
+    if is-gapful "$i"; then
+      if (( found )); then
+        printf ' ';
+      fi
+      printf '%s' "$i"
+      (( found++ ))
+    fi
+  done
+  printf '\n'
+}
+
+report-ranges() {
+  local range
+  local -i start size
+  for range; do
+    IFS=, read start size <<<"$range"
+    printf 'The first %d gapful numbers >= %d:\n' "$size" "$start"
+    gapfuls-in-range "$start" "$size"
+    printf '\n'
+  done
+}
+
+report-ranges 1,30 1000000,15 1000000000,10