Data commit

Task/Elementary-cellular-automaton/UNIX-Shell/elementary-cellular-automaton.sh

@@ -0,0 +1,36 @@
+function print_cells {
+  local chars=(. '#') cell
+  for cell; do
+    printf '%s' "${chars[$cell]}"
+  done
+  printf '\n'
+}
+
+function next_gen {
+  local rule=$1
+  shift
+  cells=("$@")
+  local -i l c r bit
+  for (( l=$#-1, c=0, r=1; c < $#;
+         l=(l+1)%$#, c+=1, r=(r+1)%$# )); do
+    local left=${cells[l]} current=${cells[c]} right=${cells[r]}
+    (( bit = 1<<(left<<2 | current<<1 | right) ))
+    printf '%d\n' $(( rule & bit ? 1 : 0 ))
+  done
+}
+
+function automaton {
+  local size=${1:-32} rule=${2:-90}
+  local stop=${3:-$(( size/2 ))}
+  local i gen cells=()
+  for (( i=0; i<size; ++i )); do
+    cells+=( $(( i == size/2 )) )
+  done
+  for (( gen=0; gen<stop; ++gen )); do
+    printf "%${#stop}d: " "$gen"
+    print_cells "${cells[@]}"
+    cells=($(next_gen "$rule" "${cells[@]}"))
+  done
+}
+
+automaton "$@"