C version

README.md

@@ -23,10 +23,9 @@ For the total hours a person should work in the day, we'll consider 08:48 (or
 At 09:00
 
 ```
-$ wc 08:00
+$ wh 08:00
 So far, you worked 01:00
 You still need to work 07:48
-You still need to work till 17:48
 ```
 
 Reasoning: By starting at 08:00, up to 12:00, the user would've worked 4
@@ -36,10 +35,9 @@ hours; going back to work at 13:00, they would still need to work 4h48m, till
 At 18:00
 
 ```
-$ wc 08:00 12:00 13:00
-So far, you worked, 09:00.
+$ wh 08:00 12:00 13:00
+So far, you worked 09:00.
 You did 00:12 hours of extra work.
-You could've left at 17:48
 ```
 
 ## Languages

c/hours.c

@@ -0,0 +1,112 @@
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "hours.h"
+
+struct hoursStruct {
+	int minutes;
+};
+
+/**
+ * Create a new hours structure.
+ */
+hours* hours_new(char *input)
+{
+	struct hoursStruct* result = NULL;
+
+	char *duplicate = malloc(sizeof(char) * strlen(input) + 1);
+	sprintf(duplicate, "%s", input);
+
+	char *colon = strchr(duplicate, ':');
+	if (colon == NULL) {
+		goto cleanup;
+	}
+
+	char* minutes_pos = colon + 1;
+	*colon = '\0';
+
+	int hours = atoi(duplicate);
+	int minutes = atoi(minutes_pos);
+
+	if (hours < 0 || hours > 23) {
+		goto cleanup;
+	}
+
+	if (minutes < 0 || minutes > 59) {
+		goto cleanup;
+	}
+
+	int total_minutes = hours * 60 + minutes;
+
+	result = malloc(sizeof(struct hoursStruct));
+	result->minutes = total_minutes;
+
+cleanup:
+	free(duplicate);
+	return result;
+}
+
+/**
+ * Create an Hours with the current time.
+ */
+hours* hours_right_now()
+{
+	struct hoursStruct* result = malloc(sizeof(struct hoursStruct));
+	time_t right_now;
+	time(&right_now);
+	struct tm* local = localtime(&right_now);
+
+	result->minutes = local->tm_hour * 60 + local->tm_min;
+	return result;
+}
+
+/**
+ * Substract one hour from another. Returns a new hours struct.
+ */
+hours* hours_sub(hours* self, hours* other)
+{
+	struct hoursStruct* result = malloc(sizeof(struct hoursStruct));
+	result->minutes = other->minutes - self->minutes;
+	return result;
+}
+
+/**
+ * Add one hour to to another. Returns a new hours struct.
+ */
+hours* hours_add(hours* self, hours* other)
+{
+	struct hoursStruct* result = malloc(sizeof(struct hoursStruct));
+	result->minutes = other->minutes + self->minutes;
+	return result;
+}
+
+/**
+ * Pretty display for hours.
+ */
+char *hours_display(hours* self)
+{
+	int hours = (int)ceil(self->minutes / 60);
+	int minutes = self->minutes - (hours * 60);
+
+	char* result = malloc(sizeof(char) * 6);	// XX:XX\0
+	sprintf(result, "%02d:%02d", hours, minutes);
+	return result;
+}
+
+/**
+ * Checks if the hours happens before the other; returns -1 if it is earlier or 1 if it is later.
+ */
+int hours_preceed(hours* self, hours* other) {
+	return self->minutes < other->minutes
+		? -1
+		: 1;
+}
+
+/**
+ * Free the memory used by the hours.
+ */
+void hours_free(hours* self) {
+	free(self);
+}

c/hours.h

@@ -0,0 +1,14 @@
+#ifndef HOURS_H
+#define HOURS_H
+
+typedef struct hoursStruct hours;
+
+hours* hours_new(char *input);
+hours* hours_right_now();
+hours* hours_sub(hours* self, hours* other);
+hours* hours_add(hours* self, hours* other);
+char* hours_display(hours* self);
+void hours_free(hours* self);
+int hours_preceed(hours* self, hours* other);
+
+#endif

c/main.c

@@ -0,0 +1,85 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "hours.h"
+
+int main(int argc, char* argv[]) {
+	hours *start = NULL;
+	hours *lunch_break = NULL;
+	hours *lunch_return = NULL;
+
+	if (argc <= 1) {
+		printf("Usage: wh START_TIME [LUNCH_BREAK] [LUNCH_RETURN]\n");
+		return EXIT_FAILURE;
+	}
+
+	if (argc >= 2) {
+		start = hours_new(argv[1]);
+		if (start == NULL) {
+			printf("Invalid START_TIME\n");
+			return EXIT_FAILURE;
+		}
+	}
+
+	if (argc >= 3) {
+		lunch_break = hours_new(argv[2]);
+		if (lunch_break == NULL) {
+			printf("Invalid LUNCH_BREAK\n");
+			return EXIT_FAILURE;
+		}
+	} else {
+		lunch_break = hours_new("12:00");
+	}
+
+	if (argc >= 4) {
+		lunch_return = hours_new(argv[3]);
+		if (lunch_return == NULL) {
+			printf("Invalid LUNCH_RETURN\n");
+			return EXIT_FAILURE;
+		}
+	} else {
+		lunch_return = hours_new("13:00");
+	}
+
+	hours* now = hours_right_now();
+	hours* so_far;
+	if (hours_preceed(now, lunch_return) == -1) {
+		so_far = hours_sub(start, now);
+	} else {
+		hours* before_lunch = hours_sub(start, lunch_break);
+		hours* after_lunch = hours_sub(lunch_return, now);
+
+		so_far = hours_add(before_lunch, after_lunch);
+
+		hours_free(before_lunch);
+		hours_free(after_lunch);
+	}
+
+	char *display = hours_display(so_far);
+
+	printf("So far, you've worked %s\n", display);
+
+	hours* must_work = hours_new("08:48");
+	if (hours_preceed(so_far, must_work) == -1) {
+		hours* remaining = hours_sub(so_far, must_work);
+		char *still = hours_display(remaining);
+		printf("You still need to work %s\n", still);
+		free(still);
+		hours_free(remaining);
+	} else {
+		hours* exceeding = hours_sub(must_work, so_far);
+		char* extra = hours_display(exceeding);
+		printf("You did %s of extra work\n", extra);
+		free(extra);
+		hours_free(exceeding);
+	}
+
+	free(display);
+	hours_free(so_far);
+	hours_free(now);
+	hours_free(start);
+	hours_free(lunch_break);
+	hours_free(lunch_return);
+
+	return EXIT_SUCCESS;
+}

c/makefile

@@ -0,0 +1,7 @@
+OBJS = main.o hours.o
+
+wh: $(OBJS)
+	gcc $^ -o $@
+
+%.o: %.c %.h
+	gcc -c $< -Wall