feat(Week12): Add solutions to most exercises

1 files changed, 158 insertions, 0 deletions

diff --git a/Week12/Exercise04.cpp b/Week12/Exercise04.cpp
new file mode 100644
index 0000000..b10ff9e
--- /dev/null
+++ b/Week12/Exercise04.cpp
@@ -0,0 +1,158 @@
+#include <iostream>
+
+// Функциите тук "консумират" входния низ, тоест не просто
+// превръщат буквите в някаква друга стойност, ами и инкрементират
+// указателя, така че да се пропуснат обработените букви.
+
+bool isDigit(char x) {
+	return '0' <= x && x <= '9';
+}
+
+bool digitsUntil(const char*& str, char end) {
+	bool hasAnyDigits = false;
+
+	while (*str != '\0' && *str != end) {
+		if (!isDigit(*str))
+			return false;
+		str++;
+		hasAnyDigits = true;
+	}
+
+	return hasAnyDigits && *str == end;
+}
+
+bool isInteger(const char* text) {
+	if (*text == '+' || *text == '-')
+		text++;
+
+	return digitsUntil(text, '\0');
+}
+
+bool isFloat(const char* text) {
+	if (*text == '+' || *text == '-')
+		text++;
+
+	if (!digitsUntil(text, '.'))
+		return false;
+	text++;
+	return digitsUntil(text, '\0');
+}
+
+bool isLetter(char x) {
+	return ('A' <= x && x <= 'Z') || ('a' <= x && x <= 'z');
+}
+
+bool isWord(const char* text) {
+	while (*text != '\0') {
+		if (!isLetter(*text))
+			return false;
+		text++;
+	}
+	return true;
+}
+
+// В тази функция донякъде има един проблем:
+// не проверяваме ако часа ни е 12-часов, дали часа е между 0 и 12 (вместо между 0 и 24).
+// Обаче, по условие не ни е казано да проверяваме за това, затова изпускам проверката.
+bool isTime(const char* text) {
+	if ((text[0] == 'A' || text[0] == 'P') && text[1] == 'M')
+		text += 2;
+
+	if (!isDigit(*text) && '0' <= *text && *text <= '2')
+		return false;
+	text++;
+
+	if (isDigit(*text))
+		text++;
+
+	if (*text != ':')
+		return false;
+	text++;
+
+	if (!isDigit(*text) && '0' <= *text && *text <= '5')
+		return false;
+	text++;
+
+	if (!isDigit(*text))
+		return false;
+	text++;
+
+	if ((text[0] == 'A' || text[0] == 'P') && text[1] == 'M')
+		text += 2;
+
+	return *text == '\0';
+}
+
+bool isPercentage(char* text, unsigned int size) {
+	if (!isDigit(*text))
+		return false;
+
+	if (text[size - 1] != '%')
+		return false;
+
+	text[size - 1] = '\0';
+
+	return isInteger(text) || isFloat(text);
+}
+
+char* getInput(unsigned &allocated, unsigned &size);
+
+int main() {
+	unsigned int allocated, size;
+	char* text = getInput(allocated, size);
+
+	if (size == 0) {
+		std::cout << "other" << std::endl;
+	}
+	else if (isInteger(text)) {
+		std::cout << "integer" << std::endl;
+	}
+	else if (isFloat(text)) {
+		std::cout << "float" << std::endl;
+	}
+	else if (isWord(text)) {
+		std::cout << "word" << std::endl;
+	}
+	else if (isTime(text)) {
+		std::cout << "time" << std::endl;
+	}
+	else if (isPercentage(text, size)) {
+		std::cout << "percentage" << std::endl;
+	}
+	else {
+		std::cout << "other" << std::endl;
+	}
+
+	delete[] text;
+
+	return 0;
+}
+
+char* getInput(unsigned &allocated, unsigned &size) {
+	allocated = 8;
+	size = 0;
+
+	char* input = new char[allocated];
+
+	char curr;
+	std::cin.get(curr);
+	while (curr != '\n') {
+		input[size++] = curr;
+		std::cin.get(curr);
+
+		// Реоразмеряване
+		if (size >= allocated) {
+			allocated *= 2;
+			char* newSentenceArray = new char[allocated];
+
+			for (unsigned i = 0; i < size; i++)
+				newSentenceArray[i] = input[i];
+
+			delete[] input;
+			input = newSentenceArray;
+		}
+	}
+	input[size] = '\0';
+
+	return input;
+}