Data commit

Task/Run-length-encoding/UNIX-Shell/run-length-encoding-1.sh

@@ -0,0 +1,45 @@
+encode() {
+    local phrase=$1
+    [[ -z $phrase ]] && return
+    local result="" count=0 char=${phrase:0:1}
+    for ((i = 0; i < ${#phrase}; i++)); do
+        if [[ ${phrase:i:1} == "$char" ]]; then
+            ((count++))
+        else
+            result+="$(encode_sequence "$count" "$char")"
+            char=${phrase:i:1}
+            count=1
+        fi
+    done
+    result+="$(encode_sequence "$count" "$char")"
+    echo "$result"
+}
+
+encode_sequence() {
+    local count=$1 char=$2
+    ((count == 1)) && count=""
+    echo "${count}${char}"
+}
+
+decode() {
+    local phrase=$1
+    local result=""
+    local count char
+
+    while [[ $phrase =~ ([[:digit:]]+)([^[:digit:]]) ]]; do
+        printf -v phrase "%s%s%s" \
+            "${phrase%%${BASH_REMATCH[0]}*}" \
+            "$(repeat "${BASH_REMATCH[1]}" "${BASH_REMATCH[2]}")" \
+            "${phrase#*${BASH_REMATCH[0]}}"
+    done
+    echo "$phrase"
+}
+
+repeat() {
+    local count=$1 char=$2
+    local result
+    # string of count spaces
+    printf -v result "%*s" "$count" ""
+    # replace spaces with the char
+    echo "${result// /$char}"
+}

Task/Run-length-encoding/UNIX-Shell/run-length-encoding-2.sh

@@ -0,0 +1,5 @@
+str="WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
+enc=$(encode "$str")
+dec=$(decode "$enc")
+declare -p str enc dec
+[[ $str == "$dec" ]] && echo success || echo failure