add random function

Makefile

@@ -2,7 +2,7 @@ CC=gcc
 CFLAGS=-Wall -Werror
 CPPFLAGS+=-Isrc/include
 #LDFLAGS=-lm
-SRC=src/sort.c
+SRC=src/sort.c src/random.c
 OBJ=$(SRC:.c=.o)
 
 all: sort informe

src/include/random.h

@@ -0,0 +1,4 @@
+#ifndef _SORT_RANDOM
+	#define _SORT_RANDOM
+	int gen_rand(int min, int max);
+#endif

src/random.c

@@ -0,0 +1,12 @@
+#include <stdlib.h>
+#include <time.h>
+
+static int sort_rand_initialized = 0;
+
+int gen_rand(int min, int max) {
+	if (sort_rand_initialized == 0) {
+		srand((unsigned int) time(NULL));
+		sort_rand_initialized = 1;
+	}
+	return rand() % (max + 1 - min) + min;
+}