1 files changed, 59 insertions, 0 deletions
diff --git a/challenge-119/paulo-custodio/cpp/ch-2.cpp b/challenge-119/paulo-custodio/cpp/ch-2.cpp
new file mode 100644
index 0000000000..be94768168
--- /dev/null
+++ b/challenge-119/paulo-custodio/cpp/ch-2.cpp
@@ -0,0 +1,59 @@
+/*
+Challenge 119
+
+TASK #2 - Sequence without 1-on-1
+Submitted by: Cheok-Yin Fung
+Write a script to generate sequence starting at 1. Consider the increasing
+sequence of integers which contain only 1's, 2's and 3's, and do not have any
+doublets of 1's like below. Please accept a positive integer $N and print the
+$Nth term in the generated sequence.
+
+1, 2, 3, 12, 13, 21, 22, 23, 31, 32, 33, 121, 122, 123, 131, ...
+
+Example
+Input: $N = 5
+Output: 13
+
+Input: $N = 10
+Output: 32
+
+Input: $N = 60
+Output: 2223
+*/
+
+#include <iostream>
+using namespace std;
+
+bool num_ok(int n) {
+    int last_digit, digit;
+
+    if (n <= 0)
+        return false;
+    while (n > 0) {
+        last_digit = digit;
+        digit = n % 10;
+        n /= 10;
+        if (digit < 1 || digit > 3 || (digit == 1 && last_digit == 1))
+            return false;
+    }
+    return true;
+}
+
+int next_seq(int seq) {
+    while (1) {
+        seq++;
+        if (num_ok(seq))
+            return seq;
+    }
+}
+
+int main(int argc, char* argv[]) {
+    int num = 0;
+    if (argc == 2) num = atoi(argv[1]);
+
+    int seq = 0;
+    for (int i = 0; i < num; i++)
+        seq = next_seq(seq);
+
+    cout << seq << endl;
+}