Add Awk solution to challenge 99

3 files changed, 109 insertions, 1 deletions

diff --git a/challenge-098/paulo-custodio/awk/ch-1.awk b/challenge-098/paulo-custodio/awk/ch-1.awk
index 51d8f3a8f6..4711a7babb 100644
--- a/challenge-098/paulo-custodio/awk/ch-1.awk
+++ b/challenge-098/paulo-custodio/awk/ch-1.awk
@@ -31,7 +31,7 @@ function readN(filename, read_len) {
 
 BEGIN {
     for (i = 1; i < ARGC - 1; i += 2) {
-        text = readN(ARGV[i], ARGV[i+1]);
+        text = readN(ARGV[i], ARGV[i+1])
         print text
     }
     exit 0
diff --git a/challenge-099/paulo-custodio/awk/ch-1.awk b/challenge-099/paulo-custodio/awk/ch-1.awk
new file mode 100644
index 0000000000..e69e053735
--- /dev/null
+++ b/challenge-099/paulo-custodio/awk/ch-1.awk
@@ -0,0 +1,58 @@
+#!/usr/bin/gawk
+
+# TASK #1 › Pattern Match
+# Submitted by: Mohammad S Anwar
+# You are given a string $S and a pattern $P.
+#
+# Write a script to check if given pattern validate the entire string.
+# Print 1 if pass otherwise 0.
+#
+# The patterns can also have the following characters:
+#
+# ? - Match any single character.
+# * - Match any sequence of characters.
+# Example 1:
+# Input: $S = "abcde" $P = "a*e"
+# Output: 1
+# Example 2:
+# Input: $S = "abcde" $P = "a*d"
+# Output: 0
+# Example 3:
+# Input: $S = "abcde" $P = "?b*d"
+# Output: 0
+# Example 4:
+# Input: $S = "abcde" $P = "a*c?e"
+# Output: 1
+
+function match_pattern(s, p) {
+    while (1) {
+        if (s=="" && p=="")         # string and pattern finished
+            return 1
+        else if (s=="" || p=="")    # either string or pattern finished
+            return 0
+        else if (p ~ /^\?/) {       # match any character
+            s = substr(s, 2)
+            p = substr(p, 2)
+        }
+        else if (p ~ /^\*/) {       # match any sub-sequence
+            p = substr(p, 2)
+            for (i = 1; i <= length(s); i++) {
+                if (match_pattern(substr(s, i), p))
+                    return 1
+            }
+            return 0
+        }
+        else if (substr(p,1,1) != substr(s,1,1)) {  # chars different
+            return 0
+        }
+        else {                      # search next char
+            s = substr(s, 2)
+            p = substr(p, 2)
+        }
+    }
+}
+
+BEGIN {
+    print match_pattern(ARGV[1], ARGV[2])
+    exit 0
+}
diff --git a/challenge-099/paulo-custodio/awk/ch-2.awk b/challenge-099/paulo-custodio/awk/ch-2.awk
new file mode 100644
index 0000000000..5c7a28d2fb
--- /dev/null
+++ b/challenge-099/paulo-custodio/awk/ch-2.awk
@@ -0,0 +1,50 @@
+#!/usr/bin/gawk
+
+# TASK #2 › Unique Subsequence
+# Submitted by: Mohammad S Anwar
+# You are given two strings $S and $T.
+#
+# Write a script to find out count of different unique subsequences matching
+# $T without changing the position of characters.
+#
+# Example 1:
+# Input: $S = "littleit', $T = 'lit'
+# Output: 5
+#
+#     1: [lit] tleit
+#     2: [li] t [t] leit
+#     3: [li] ttlei [t]
+#     4: litt [l] e [it]
+#     5: [l] ittle [it]
+# Example 2:
+# Input: $S = "london', $T = 'lon'
+# Output: 3
+#
+#     1: [lon] don
+#     2: [lo] ndo [n]
+#     3: [l] ond [on]
+
+function count_subsequences(s, t) {
+    while (1) {
+        if (t=="") {            # t is empty, matched
+            return 1
+        }
+        else if (s=="") {       # s is empty, did not match
+            return 0
+        }
+        else if (substr(s,1,1) == substr(t,1,1)) {  # same char,
+                                                    # check two paths matching
+                                                    # and not matching
+            return count_subsequences(substr(s,2), substr(t,2)) \
+                 + count_subsequences(substr(s,2), t)
+        }
+        else {                  # different char, keep pattern
+            s = substr(s,2)
+        }
+    }
+}
+
+BEGIN {
+    print count_subsequences(ARGV[1], ARGV[2])
+    exit 0
+}