commit be39097f63ae186a3dc08fc4de7c1116585a2c0d
Author: hasslesstech <user1@109.86.70.81>
Date:   Sat Sep 21 16:39:10 2024 +0300

    initial commit

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..44270b2
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,8 @@
+CFLAGS = -I lib/ -O3 -Wall -Werror -Wextra -Wpedantic
+
+build: src/main.c
+	mkdir -p bin/
+	gcc $(CFLAGS) -o bin/main \
+		src/terminal_colors.c \
+		src/main.c \
+		-lm
diff --git a/lib/terminal_colors.h b/lib/terminal_colors.h
new file mode 100644
index 0000000..0a9b655
--- /dev/null
+++ b/lib/terminal_colors.h
@@ -0,0 +1,5 @@
+#define COLOR_RED 1
+
+void clear_color(void);
+
+void set_color(int  color_id);
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..5a6fefe
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,180 @@
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+
+#include "terminal_colors.h"
+
+static int
+retrieve_double_from_string(double*  p_target,
+                            char*    p_source)
+{
+    return sscanf(p_source, "%lf", p_target);
+}
+
+static int
+retrieve_inputs_from_argv(char**   argv,
+                          double*  px,
+                          double*  py)
+{
+    /*
+     * In binary form, shows which values have
+     * failed to be read. If specific bit is set,
+     * the corresponding value has not been read
+     * correctly.
+     *
+     * return code: 00
+     *              ^^
+     *              ||
+     *              |`- bit 0 represents value of "x"
+     *              |
+     *              `- bit 1 represents value of "y"
+     */
+    int return_code = 0;
+
+    if (1 != retrieve_double_from_string(px, argv[1]))
+        return_code |= 0x1;
+
+    if (1 != retrieve_double_from_string(py, argv[2]))
+        return_code |= 0x2;
+
+    return return_code;
+}
+
+
+static void
+retrieve_double_from_stdin(double*  p_target,
+                           char*    p_label)
+{
+    char retrieved_string[128];
+
+    for (int attempts = 0; attempts < 10000; ++attempts)
+    {
+        printf("Enter %s: ", p_label);
+
+        fgets(retrieved_string, 127, stdin);
+
+        int received_args = sscanf(retrieved_string, "%lf", p_target);
+
+        if (1 == received_args)
+            break;
+
+        puts("Please, try again.");
+    }
+}
+
+static void
+retrieve_inputs_from_stdin(double*  px,
+                           double*  py)
+{
+    retrieve_double_from_stdin(px, "x");
+    retrieve_double_from_stdin(py, "y");
+}
+
+static void
+calculate_result(double*  z1,
+                 double*  z2,
+                 double*  x,
+                 double*  y)
+{
+    double temp1;
+
+    *z1   = cos(*x);
+    *z1   = *z1 * *z1
+          * *z1 * *z1;
+    *z1  += sin(2**y);
+    temp1 = sin(*x/2);
+    *z1  += temp1 * temp1
+          / 4 - 1;
+
+    *z2   = sin(*x + *y);
+    *z2  += sin(*x - *y);
+}
+
+static void
+print_padding(int  padding_length)
+{
+    for (int i = 0; i < padding_length; i++)
+    {
+        fputs(" ", stdout);
+    }
+}
+
+static void
+print_argument_error(char**  argv,
+                     int     argc,
+                     int     wrong_argument_index)
+{
+    fputs("[Error] ", stdout);
+
+    int padding_length = 0;
+
+    for (int i = 0; i < argc; ++i)
+    {
+        if (i < wrong_argument_index)
+            padding_length += strlen(argv[i]) + 1;
+    }
+
+    for (int i = 0; i < argc; ++i)
+    {
+        if (i == wrong_argument_index)
+            set_color(COLOR_RED);
+
+        fputs(argv[i], stdout);
+
+        if (i == wrong_argument_index)
+            clear_color();
+
+        fputs(" ", stdout);
+    }
+
+    fputs("\n[Error]", stdout);
+    print_padding(padding_length);
+    puts(" ^ not a valid (double) value.");
+}
+
+static void
+print_error_message(char**  argv,
+                    int     argc,
+                    int     error_code)
+{
+    puts("[Error] Incorrect CLI argument input.");
+
+    if (error_code & 0x1)
+        print_argument_error(argv, argc, 1);
+
+    if (error_code & 0x2)
+        print_argument_error(argv, argc, 2);
+}
+
+int
+main(int     argc,
+     char**  argv)
+{
+    double x,
+           y,
+           z1,
+           z2;
+
+    if (3 == argc)
+    {
+        int read_errors = retrieve_inputs_from_argv(argv, &x, &y);
+
+        if (read_errors)
+        {
+            print_error_message(argv, argc, read_errors);
+            return 1;
+        }
+    }
+    else
+    {
+        retrieve_inputs_from_stdin(&x, &y);
+    }
+
+    calculate_result(&z1, &z2, &x, &y);
+
+    printf("Results:\nz1 = %.10lf\nz2 = %.10lf\n", z1, z2);
+
+    return 0;
+}
+
+
diff --git a/src/terminal_colors.c b/src/terminal_colors.c
new file mode 100644
index 0000000..4a1d40b
--- /dev/null
+++ b/src/terminal_colors.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+void
+clear_color()
+{
+    fputs("\033[0m", stdout);
+}
+
+/*
+ * Color codes:
+ * 1 - red
+ */
+void set_color(int  color_code)
+{
+    switch (color_code)
+    {
+        case 1:
+            fputs("\033[31;1m", stdout);
+            break;
+        default:
+            break;
+    }
+}