Add C solution

3 files changed, 82 insertions, 1 deletions

diff --git a/challenge-048/paulo-custodio/c/ch-2.c b/challenge-048/paulo-custodio/c/ch-2.c
new file mode 100644
index 0000000000..32ed45df01
--- /dev/null
+++ b/challenge-048/paulo-custodio/c/ch-2.c
@@ -0,0 +1,57 @@
+/*
+Challenge 048
+
+TASK #2
+Palindrome Dates
+Write a script to print all Palindrome Dates between 2000 and 2999. The format
+of date is mmddyyyy. For example, the first one was on October 2, 2001 as it is
+represented as 10022001.
+*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+bool is_leap_year(int y) {
+    return y % 400 == 0 ? true : y % 100 == 0 ? false : y % 4 == 0 ? true : false;
+}
+
+int days_of_month(int y, int m) {
+    switch (m) {
+    case 1: case 3: case 5: case 7: case 8: case 10: case 12: return 31;
+    case 4: case 6: case 9: case 11: return 30;
+    case 2: return is_leap_year(y) ? 29 : 28;
+    default: assert(0); return -1;
+    }
+}
+
+bool is_palindrome(const char* str) {
+    int i = 0, j = strlen(str)-1;
+    while (i < strlen(str) && j >= 0) {
+        if (str[i] != str[j])
+            return false;
+        i++; j--;
+    }
+    return true;
+}
+
+void print_palindrome_dates(int start_year, int end_year) {
+    char date[BUFSIZ];
+
+    for (int y = start_year; y <= end_year; y++) {
+        for (int m = 1; m <= 12; m++) {
+            int eom = days_of_month(y, m);
+            for (int d = 1; d <= eom; d++) {
+                sprintf(date, "%02d%02d%04d", m, d, y);
+                if (is_palindrome(date))
+                    printf("%s\n", date);
+            }
+        }
+    }
+}
+
+int main() {
+    print_palindrome_dates(2000, 2999);
+}
diff --git a/challenge-048/paulo-custodio/perl/ch-2.pl b/challenge-048/paulo-custodio/perl/ch-2.pl
index 27e9fe5bc8..be0dfde09e 100644
--- a/challenge-048/paulo-custodio/perl/ch-2.pl
+++ b/challenge-048/paulo-custodio/perl/ch-2.pl
@@ -12,7 +12,7 @@ use Modern::Perl;
 use DateTime;
 
 my $dt = DateTime->new(year=>2000, month=>1, day=>1);
-while ($dt->year < 2100) {
+while ($dt->year <= 2999) {
     my $txt = $dt->strftime("%m%d%Y");
     say $txt if reverse($txt) eq $txt;  # is palindrome
     $dt->add(days=>1);
diff --git a/challenge-048/paulo-custodio/t/test-2.yaml b/challenge-048/paulo-custodio/t/test-2.yaml
index fdb31f1c58..01f6c61b09 100644
--- a/challenge-048/paulo-custodio/t/test-2.yaml
+++ b/challenge-048/paulo-custodio/t/test-2.yaml
@@ -15,3 +15,27 @@
             |07022070
             |08022080
             |09022090
+            |10122101
+            |01122110
+            |11122111
+            |02122120
+            |12122121
+            |03122130
+            |04122140
+            |05122150
+            |06122160
+            |07122170
+            |08122180
+            |09122190
+            |10222201
+            |01222210
+            |11222211
+            |02222220
+            |12222221
+            |03222230
+            |04222240
+            |05222250
+            |06222260
+            |07222270
+            |08222280
+            |09222290