Data commit

Task/Balanced-brackets/UNIX-Shell/balanced-brackets.sh

@@ -0,0 +1,38 @@
+generate() {
+    local b=()
+    local i j tmp
+    for ((i=1; i<=$1; i++)); do
+        b+=( '[' ']')
+    done
+    for ((i=${#b[@]}-1; i>0; i--)); do
+        j=$(rand $i)
+        tmp=${b[j]}
+        b[j]=${b[i]}
+        b[i]=$tmp
+    done
+    local IFS=
+    echo "${b[*]}"
+}
+
+# a random number in the range [0,n)
+rand() {
+    echo $(( $RANDOM % $1 ))
+}
+
+balanced() {
+    local -i lvl=0
+    local i
+    for ((i=0; i<${#1}; i++)); do
+        case ${1:i:1} in
+            '[') ((lvl++));;
+            ']') (( --lvl < 0 )) && return 1;;
+        esac
+    done
+    (( lvl == 0 )); return $?
+}
+
+for ((i=0; i<=10; i++)); do
+    test=$(generate $i)
+    balanced "$test" && result=OK || result="NOT OK"
+    printf "%s\t%s\n" "$test" "$result"
+done