freqs.cc

freqs.cc

/**
* Author: reefridge <reefridgerator@gmail.com>
* Compilation: `g++ freqs.cpp -o freqs`
* Synopsis: `freqs`
*/
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cctype>

template<class T> class Container {
public:
	T* elements = new T[0];
	unsigned int len = 0;

	~Container() {
		clear();
	}

	void clear() {
		delete[] elements;
		elements = new T[0];
		len = 0;
	}

	void operator +=(T el) {
		T* temp = new T[len];

		for (int i = 0; i < len; i++) {
			temp[i] = elements[i];
		}

		delete[] elements;

		elements = new T[len + 1];

		for (int i = 0; i < len; i++) {
			elements[i] = temp[i];
		}

		delete[] temp;

		elements[len++] = el;
	}
};

class Word : public Container<char> {
public:
	void to_lower_case() {
		for (int j = 0; j < len; j++) {
			elements[j] = tolower(elements[j]);
		}
	}

	void terminate() {
		Container<char>::operator+=('\0');
	}
};

bool operator ==(const Word& that, const Word& other) {
	const char *p1 = that.elements;
	const char *p2 = other.elements;

	while (*p1 != '\0') {
		if (*p1 != *p2) {

			return false;
		}

		p1++; p2++;
	}

	return true;
}

struct FreqRecord {
	Word word;
	unsigned int count = 1;
};

class Freqs : public Container<FreqRecord> {
public:
	int index_record_by_word(const Word& word) {
		int result = -1;

		for (int j = 0; j < len; j++) {
			if (elements[j].word == word) {
				result = j;
				break;
			};
		}

		return result;
	}

	void increment(const Word word) {
		int idx = index_record_by_word(word);

		if (idx != -1) {
			elements[idx].count++;
		}
		else {
			FreqRecord rec;
			rec.word = word;
			Container<FreqRecord>::operator+=(rec);
		}
	}
};

bool is_alpha(char c) {
	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
}

int main(int argc, char** argv) {
	Word word;
	Freqs freqs;

	char input[] = "The time has come, the walrus said, to talk of many things.";
	char input_len = sizeof(input);
	printf("%s %d\n", input, sizeof(input));

	for (int i = 0; i < input_len; i++) {
		if (is_alpha(input[i])) {
			word += input[i];
		}
		else if (word.len != 0) {
			word.to_lower_case();
			word.terminate();

			freqs.increment(word);

			word.clear();
		}
	}

	for (int i = 0; i < freqs.len; i++) {
		printf("%s %d\n", freqs.elements[i].word.elements, freqs.elements[i].count);
	}

	return 0;
}