Merge branch 'master' of github.com:seaker/perlweeklychallenge-club

2 files changed, 122 insertions, 0 deletions

diff --git a/challenge-102/paulo-custodio/cpp/ch-1.cpp b/challenge-102/paulo-custodio/cpp/ch-1.cpp
new file mode 100644
index 0000000000..01d88ccd5a
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+++ b/challenge-102/paulo-custodio/cpp/ch-1.cpp
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+/*
+Challenge 102
+
+TASK #1 › Rare Numbers
+Submitted by: Mohammad S Anwar
+
+You are given a positive integer $N.
+
+Write a script to generate all Rare numbers of size $N if exists. Please
+checkout the page for more information about it.
+Examples
+
+(a) 2 digits: 65
+(b) 6 digits: 621770
+(c) 9 digits: 281089082
+*/
+
+#include <iostream>
+#include <cmath>
+
+int ipow(int base, int exp) {
+    int result = 1;
+    for (;;) {
+        if (exp & 1)
+            result *= base;
+        exp >>= 1;
+        if (!exp)
+            break;
+        base *= base;
+    }
+    return result;
+}
+
+int invert_number(int r) {
+    int r1 = 0;
+    while (r != 0) {
+        r1 = r1 * 10 + (r % 10);
+        r = r / 10;
+    }
+    return r1;
+}
+
+bool is_perfect_square(int n) {
+    double s = sqrt((double)n);
+    if (floor(s) == s)
+        return true;
+    else
+        return false;
+}
+
+void print_rare(int n) {
+    int start = ipow(10, n - 1);
+    int end = ipow(10, n );
+    for (int r = start; r < end; r++) {
+        int r1 = invert_number(r);
+        if (is_perfect_square(r + r1) && r >= r1 && is_perfect_square(r - r1))
+            std::cout << r << std::endl;
+    }
+}
+
+int main(int argc, char* argv[]) {
+    if (argc != 2) {
+        std::cerr << "Usage: ch-1 N" << std::endl;
+        return EXIT_FAILURE;
+    }
+    else
+        print_rare(atoi(argv[1]));
+}
diff --git a/challenge-102/paulo-custodio/cpp/ch-2.cpp b/challenge-102/paulo-custodio/cpp/ch-2.cpp
new file mode 100644
index 0000000000..24fbf2fb06
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+++ b/challenge-102/paulo-custodio/cpp/ch-2.cpp
@@ -0,0 +1,54 @@
+/*
+Challenge 102
+
+TASK #2 › Hash-counting String
+Submitted by: Stuart Little
+
+You are given a positive integer $N.
+
+Write a script to produce Hash-counting string of that length.
+
+The definition of a hash-counting string is as follows:
+- the string consists only of digits 0-9 and hashes, ‘#’
+- there are no two consecutive hashes: ‘##’ does not appear in your string
+- the last character is a hash
+- the number immediately preceding each hash (if it exists) is the position
+of that hash in the string, with the position being counted up from 1
+
+It can be shown that for every positive integer N there is exactly one such
+length-N string.
+Examples:
+
+(a) "#" is the counting string of length 1
+(b) "2#" is the counting string of length 2
+(c) "#3#" is the string of length 3
+(d) "#3#5#7#10#" is the string of length 10
+(e) "2#4#6#8#11#14#" is the string of length 14
+*/
+
+#include <iostream>
+#include <string>
+
+std::string hash_count(int n) {
+    std::string str(n, ' ');
+    int i = n - 1;
+    while (i >= 0) {
+        int pos = i + 1;
+        str[i--] = '#';
+        while (i >= 0 && pos != 0) {
+            str[i--] = '0' + (pos % 10);
+            pos /= 10;
+        }
+    }
+    return str;
+}
+
+
+int main(int argc, char* argv[]) {
+    if (argc != 2) {
+        std::cerr << "Usage: ch-1 N" << std::endl;
+        return EXIT_FAILURE;
+    }
+    else 
+        std::cout << hash_count(atoi(argv[1])) << std::endl;
+}