series: iteration 1

cpp/series/series.cpp

@@ -0,0 +1,54 @@
+#include "series.h"
+
+#include <algorithm>
+#include <stdexcept>
+
+namespace series {
+
+using namespace std;
+
+
+namespace {
+
+inline int char_to_digit(char ch)
+{
+    if (!isdigit(ch))
+        throw domain_error("not a digit");
+
+    return ch - '0';
+}
+
+}
+
+
+digits_t digits(const string &input)
+{
+    digits_t result(input.size());
+
+    transform(input.cbegin(), input.cend(), result.begin(), char_to_digit);
+
+    return result;
+}
+
+slice_t slice(const string &input, size_t size)
+{
+    if (size > input.size())
+        throw domain_error("not enough digits to slice");
+
+    if (size == 0)
+        return slice_t();
+
+    digits_t input_digits = digits(input);
+    slice_t  result;
+
+    auto begin = input_digits.cbegin();
+    auto end   = begin + size - 1;
+
+    while (end != input_digits.cend())
+        result.push_back(digits_t(begin++, ++end));
+
+    return result;
+}
+
+
+}

cpp/series/series.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#define EXERCISM_RUN_ALL_TESTS
+
+#include <string>
+#include <vector>
+
+namespace series {
+
+typedef std::vector<int>              digits_t;
+typedef std::vector<std::vector<int>> slice_t;
+
+digits_t digits(const std::string &input);
+slice_t  slice(const std::string &input, std::size_t size);
+
+}