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Task/ABC-Problem/UNIX-Shell/abc-problem.sh

@@ -0,0 +1,39 @@
+can_build_word() {
+    if [[ $1 ]]; then
+        can_build_word_rec "$1" BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM
+    else
+        return 1
+    fi
+}
+
+can_build_word_rec() {
+    [[ -z $1 ]] && return 0
+
+    local -u word=$1       # uppercase the first parameter
+    shift
+    local blocks=("$@")
+
+    # see if we have a block for the first letter
+    local letter=${word:0:1} indices=() i
+    for (( i=0; i<${#blocks[@]}; i++ )); do
+        if [[ ${blocks[i]} == *$letter* ]]; then
+            indices+=($i)
+        fi
+    done
+    (( ${#indices[@]} == 0 )) && return 1
+
+    local tmp
+    for i in ${indices[@]}; do
+        tmp=( "${blocks[@]}" )
+        unset "tmp[$i]"
+        can_build_word_rec "${word:1}" "${tmp[@]}" && return 0
+    done
+
+    return 1
+}
+
+words=( "" A BARK Book treat COMMON Squad confuse )
+for word in "${words[@]}"; do
+    can_build_word "$word" "${blocks[@]}" && ans=yes || ans=no
+    printf "%s\t%s\n" "$word" $ans
+done