diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..87f6767
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+main*
\ No newline at end of file
diff --git a/Cviko4_1/Makefile b/Cviko4_1/Makefile
new file mode 100644
index 0000000..2d8af15
--- /dev/null
+++ b/Cviko4_1/Makefile
@@ -0,0 +1,12 @@
+all: main
+
+CC = clang
+override CFLAGS += -std=c11 -Wall -Wextra -Wno-unused-variable -Wno-unused-parameter -Wno-unused-result -Wno-unknown-pragmas -pedantic -lm
+
+main: main.c
+	$(CC) $(CFLAGS) -O0 ./*.c -o "$@"
+run: main
+	./main $(ARGS)
+
+clean:
+	rm -f main main-*
diff --git a/Cviko4_1/types.h b/Cviko4_1/types.h
new file mode 100644
index 0000000..fcc2fe2
--- /dev/null
+++ b/Cviko4_1/types.h
@@ -0,0 +1,18 @@
+/**
+ * Hlavičkový soubor types.h
+ *
+ *     OBSAH V TOMTO SOUBROU NEUPRAVUJTE!
+ */
+
+#include <stdbool.h>
+
+#ifndef TYPES_H
+#define TYPES_H
+
+// DEKLAROVANÉ HLAVIČKY FUNKCÍ NIJAK NEMĚŇTE
+
+bool is_alpha(char c);
+
+bool is_name(char arr[]);
+
+#endif
diff --git a/Cviko4_2/Makefile b/Cviko4_2/Makefile
new file mode 100644
index 0000000..2d8af15
--- /dev/null
+++ b/Cviko4_2/Makefile
@@ -0,0 +1,12 @@
+all: main
+
+CC = clang
+override CFLAGS += -std=c11 -Wall -Wextra -Wno-unused-variable -Wno-unused-parameter -Wno-unused-result -Wno-unknown-pragmas -pedantic -lm
+
+main: main.c
+	$(CC) $(CFLAGS) -O0 ./*.c -o "$@"
+run: main
+	./main $(ARGS)
+
+clean:
+	rm -f main main-*
diff --git a/Cviko4_2/types.h b/Cviko4_2/types.h
new file mode 100644
index 0000000..918ca81
--- /dev/null
+++ b/Cviko4_2/types.h
@@ -0,0 +1,20 @@
+/**
+ * Hlavičkový soubor types.h
+ *
+ *     OBSAH V TOMTO SOUBROU NEUPRAVUJTE!
+ */
+
+#include <stdbool.h>
+
+#ifndef TYPES_H
+#define TYPES_H
+
+// DEKLAROVANÉ HLAVIČKY FUNKCÍ NIJAK NEMĚŇTE
+
+int get_max(int array[], int length);
+
+int get_sum(int array[], int length);
+
+bool values_are_smaller_than(int array1[], int array2[], int array_length);
+
+#endif
diff --git a/Cviko4_3/Makefile b/Cviko4_3/Makefile
new file mode 100644
index 0000000..2d8af15
--- /dev/null
+++ b/Cviko4_3/Makefile
@@ -0,0 +1,12 @@
+all: main
+
+CC = clang
+override CFLAGS += -std=c11 -Wall -Wextra -Wno-unused-variable -Wno-unused-parameter -Wno-unused-result -Wno-unknown-pragmas -pedantic -lm
+
+main: main.c
+	$(CC) $(CFLAGS) -O0 ./*.c -o "$@"
+run: main
+	./main $(ARGS)
+
+clean:
+	rm -f main main-*
diff --git a/Cviko4_3/types.h b/Cviko4_3/types.h
new file mode 100644
index 0000000..adcf916
--- /dev/null
+++ b/Cviko4_3/types.h
@@ -0,0 +1,26 @@
+/**
+ * Hlavičkový soubor types.h
+ *
+ *     OBSAH V TOMTO SOUBROU NEUPRAVUJTE!
+ */
+
+#include <stdbool.h>
+
+#ifndef TYPES_H
+#define TYPES_H
+
+// DEKLAROVANÉ HLAVIČKY FUNKCÍ NIJAK NEMĚŇTE
+
+bool is_in_set(int set[], int length, int value);
+
+bool is_set(int set[], int length);
+
+bool is_sorted_set(int set[], int length);
+
+void print_intersection(int set1[], int set2[], int set1_length, int set2_length);
+
+void print_union(int set1[], int set2[], int set1_length, int set2_length);
+
+void print_product(int set1[], int set2[], int set1_length, int set2_length);
+
+#endif