AWK solution for week 95/part 2

2 files changed, 51 insertions, 0 deletions

diff --git a/challenge-095/abigail/README.md b/challenge-095/abigail/README.md
index 41d284a063..24ed0ef1dc 100644
--- a/challenge-095/abigail/README.md
+++ b/challenge-095/abigail/README.md
@@ -20,6 +20,7 @@ Output: 0
 ~~~~
 
 ### Solutions
+* [awk](awk/ch-1.c)
 * [C](c/ch-1.c)
 * [Node](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
@@ -47,6 +48,7 @@ print $stack->min; # prints -1
 ~~~~
 
 ### Solutions
+* [awk](awk/ch-2.awk)
 * [C](c/ch-2.c)
 * [Node](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
diff --git a/challenge-095/abigail/awk/ch-2.awk b/challenge-095/abigail/awk/ch-2.awk
new file mode 100644
index 0000000000..d407cc7e74
--- /dev/null
+++ b/challenge-095/abigail/awk/ch-2.awk
@@ -0,0 +1,49 @@
+BEGIN {
+    size  = 0
+    error = "Stack is empty"
+}
+
+/^push/ {
+    #
+    # Push the argument on the stack. We use split to retrieve
+    # the argument. split() puts the various parts into its
+    # second argument -- an array. Note that arrays are indexed 1-based.
+    #
+    split($0, a, / +/)
+    stack [size += 1] = a [2]
+}
+
+/^pop/  {
+    #
+    # Popping just means reducing the size of the stack by 1.
+    # Don't let it go below 0.
+    #
+    size = size ? size - 1 : 0
+}
+
+/^top/  {
+    #
+    # Print the top of the stack, or an error if the stack is empty.
+    #
+    print size ? stack [size] : error
+}
+
+/^min/  {
+    #
+    # Find the minimum number in the stack, which we find by iterating
+    # over the array which represents the stack. If the stack is
+    # empty, we print an error message.
+    #
+    if (size) {
+        min = stack [1]
+        for (i = 2; i <= size; i ++) {
+            if (min > stack [i]) {
+                min = stack [i]
+            }
+        }
+        print min
+    }
+    else {
+        print error
+    }
+}