From f790d3968b8d5d2434ea5daca914a495e1b203a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1=C5=A1=20Kl=C3=A9ger?= <klegetom@fit.cvut.cz>
Date: Fri, 10 Oct 2025 14:39:35 +0200
Subject: [PATCH] ex-03: Simplified and optimized code

---
 exercise-03-rgb/main.c | 76 +++++-------------------------------------
 1 file changed, 9 insertions(+), 67 deletions(-)

diff --git a/exercise-03-rgb/main.c b/exercise-03-rgb/main.c
index b2b88a0..b2a047c 100644
--- a/exercise-03-rgb/main.c
+++ b/exercise-03-rgb/main.c
@@ -1,4 +1,3 @@
-#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -10,14 +9,8 @@
 #define debug(fmt, ...) fprintf(stdout, "[DEBUG %s:%d %s()] " fmt "\n", __FILE__, __LINE__, __func__, ##__VA_ARGS__)
 #endif
 
-bool is_numeric(const char* str) {
-	if(*str == '\0') return false;
-
-	for(;*str; str++) {
-		if(!isdigit(*str))
-			return false;
-	}
-	return true;
+bool is_in_rgb_range(int color) {
+	return color >= 0 && color <= 255;
 }
 
 int invalid_input() {
@@ -26,73 +19,22 @@ int invalid_input() {
 }
 
 int main() {
-	char* input = NULL;
-	size_t len;
-
-	int rgb[3];
+	int r = -1, g = -1, b = -1;
 
 	printf("Zadejte barvu v RGB formatu:\n");
 
-	ssize_t chars_read = getline(&input, &len, stdin);
+	int inputs_read = scanf(" rgb ( %d , %d , %d )", &r, &g, &b);
 
-	if(chars_read == -1) {
-		printf("Failed to read from stdin\n");
-		return EXIT_FAILURE;
-	}
-
-	// Strip out any whitespaces
-	char* dst = input;
-	for(char * src = input; *src; src++) {
-		if(!isspace(*src)) {
-			*dst++ = *src;
-		}
-	}
-	*dst = '\0';
-
-	int trimmed_len = strlen(input);
-
-	// Check whether the provided input
-	// starts with rgb(
-	// and ends with )
-	if(strncmp(input, "rgb(", 4) != 0 || input[trimmed_len - 1] != ')') {
-		debug("%s not in rgb(xxx) format", input);
+	if(inputs_read != 3) {
+		debug("Not enough inputs read");
 		return invalid_input();
 	}
 
-	input[trimmed_len - 1] = '\0';
-	char* slice = input + 4;
-
-	char* token = strtok(slice, ",");
-
-	for(int i = 0; i < 3; i++) {
-		// strtok reached end prematurely
-		if(token == NULL) {
-			debug("Too few numbers");
-			return invalid_input();
-		}
-
-		// Not a number
-		if(!is_numeric(token)) {
-			debug("%s is not a number", token);
-			return invalid_input();
-		}
-
-		int parsed = atoi(token);
-
-		if(parsed < 0 || parsed > 255) {
-			debug("%d out of RGB range", parsed);
-			return invalid_input();
-		}
-
-		rgb[i] = parsed;
-		token = strtok(NULL, ",");
-	}
-
-	if(token != NULL) {
-		debug("Too many numbers");
+	if(!is_in_rgb_range(r) || !is_in_rgb_range(g) || !is_in_rgb_range(b)) {
+		debug("Number not in range of rgb [0, 255]");
 		return invalid_input();
 	}
 
-	printf("#%02X%02X%02X\n", rgb[0], rgb[1], rgb[2]);
+	printf("#%02X%02X%02X\n", r, g, b);
 	return EXIT_SUCCESS;
 }