diff --git a/algo/second/Makefile b/algo/second/Makefile
index acbddb1..8e57d42 100644
--- a/algo/second/Makefile
+++ b/algo/second/Makefile
@@ -1,7 +1,7 @@
 CC=gcc
 CFLAGS=-Wall -lm -Wall -Werror=sign-compare -Werror=array-bounds -Werror=maybe-uninitialized -Werror=unused-parameter -Werror=maybe-uninitialized -Werror=cast-qual
 
-EXECS=knight
+EXECS=knight queens rabin_karp
 
 build_knight: knight.c
 	$(CC) $(CFLAGS) knight.c -o knight
@@ -12,5 +12,11 @@ build_queens: queens.c
 	$(CC) $(CFLAGS) queens.c -o queens
 queens_run: queens
 	./queens
+
+build_rabin_karp: rabin_karp.c
+	$(CC) $(CFLAGS) rabin_karp.c -o rabin_karp
+rabin_karp_run: rabin_karp
+	./rabin_karp
+
 clean:
 	rm -f $(EXECS)
diff --git a/algo/second/knight.c b/algo/second/knight.c
index 4670508..9635948 100644
--- a/algo/second/knight.c
+++ b/algo/second/knight.c
@@ -103,7 +103,7 @@ int sum_of_moves(int **array, int N, int x1, int y1) {
 	}
 	return sum;
 }
-/* Сумма элементов массива должна быть равна сумме чисел от 1 до N (т.е. обошли всю доску) */
+/* Сумма элементов массива должна быть равна сумме чисел от 1 до N*N (т.е. обошли всю доску) */
 int sum_check(int **array, int N) {
 	long long unsigned sum = 0;
 	long long unsigned total_sum = 0;
@@ -142,16 +142,13 @@ int check(int **array, int N, int x, int y) {
 				if (sum_check(array, N) && is_looped(array, N)) {
 					int difference = array[x][y] - 1;
 					/* Изменяем ходы, будто мы ходили с другого поля */
-					for (int x2 = 0; x2 < N; x2++) {
+					for (int x2 = 0; x2 < N; x2++)
 						for (int y2 = 0; y2 < N; y2++) {
-							if (array[x2][y2] > difference) {
+							if (array[x2][y2] > difference)
 								array[x2][y2] -= difference;
-							}
-							else {
+							else
 								array[x2][y2] = N * N + array[x2][y2] - difference;
-							}
 						}
-					}
 					return 2;
 				}
 			}
diff --git a/algo/second/queens.c b/algo/second/queens.c
index c151d08..0120db8 100644
--- a/algo/second/queens.c
+++ b/algo/second/queens.c
@@ -1,7 +1,6 @@
 /* Задача о ферзях */
 #include <stdio.h>
 #include <stdlib.h>
-#define _DEBUG
 
 /* Глобальная переменная для количества решений, удобнее, чем таскать указатель на счетчик по рекурсии */
 int SOLUTIONS = 0;
@@ -35,7 +34,7 @@ int main() {
 	lines = (int*)calloc(N, sizeof(int));
 
 	solve(chessboard, lines, N);
-	printf("%d", SOLUTIONS);
+	printf("%d\n", SOLUTIONS);
 	
 	delete_array(chessboard, N);
 	free(lines);
diff --git a/algo/second/rabin_karp.c b/algo/second/rabin_karp.c
new file mode 100644
index 0000000..53bcf5c
--- /dev/null
+++ b/algo/second/rabin_karp.c
@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <limits.h>
+#define POW 12
+
+long long unsigned hash(char* string);
+void search_pattern_in_text(char* FILE_WAY, char* STRING); 
+void get_string(char* string, long long unsigned len);
+
+int main() {
+	char *FILE_PATH = "rabin_karp.data"; 
+	char* STRING = "Let";
+	search_pattern_in_text(FILE_PATH, STRING);
+}
+
+long long unsigned hash(char* string) {
+	long long unsigned len_string = strlen(string);
+	long long unsigned result = 0;
+	for (long long unsigned i = 0; i < len_string; i++) {
+		result = (result * POW + string[i]) % ULONG_MAX;
+	}
+	return result;
+}
+void search_pattern_in_text(char *FILE_PATH, char *string) {
+	freopen(FILE_PATH, "r", stdin);
+	
+	int c;
+	long long unsigned string_len = strlen(string);
+	long long unsigned string_hash = hash(string);
+
+	/* "Текущая" подстрока, её мы будем смещать по тексту */
+	char *string_cur = (char*)calloc(string_len + 1, sizeof(char));
+	get_string(string_cur, string_len);
+	long long unsigned string_cur_hash = hash(string_cur);
+
+	long long unsigned MAX_POW = 1;
+	/* Получаем максимальную степень для элемента строки */
+	for (long long unsigned i = 1; i < string_len; i++) {
+		MAX_POW = (MAX_POW * POW) % ULONG_MAX;
+	}
+
+	for (long long unsigned  i = 0; (c = getchar()) != EOF; i++) {
+		/* Проверяем совпадение подстроки посимвольно, чтоб избежать коллизий */
+		if (string_hash == string_cur_hash) {
+			if (!strcmp(string, string_cur)) {
+				printf("%llu\n", i);
+			}
+		}
+		/* Обновляем хеш строки (для следующей подстроки) */
+		string_cur_hash = ((string_cur_hash - string_cur[0]*MAX_POW)*POW + c) % ULONG_MAX;
+	
+		/* "Смещаем" подстроку на один символ дальше */	
+		for (long long unsigned  j = 0; j < string_len - 1; j++) {
+			string_cur[j] = string_cur[j + 1];
+		}
+		string_cur[string_len - 1] = c;
+
+	}
+	free(string_cur);
+		
+	fclose(stdin);
+}
+/* Считываем только n символов */
+void get_string(char* string, long long unsigned n) {
+	int c;
+	for (long long unsigned i = 0; i < n; i++) {
+		if ((c = getchar()) != EOF)
+			string[i] = c;
+		else
+			assert(1);
+	}
+}
+
+
diff --git a/algo/second/rabin_karp.data b/algo/second/rabin_karp.data
new file mode 100644
index 0000000..64c9f74
--- /dev/null
+++ b/algo/second/rabin_karp.data
@@ -0,0 +1,16 @@
+Let me Let tell you about mv best friend. 
+His name is Yuriy. We have known each other for ages. 
+We live in the same town and went to the same school. 
+Now Let we study at the same university And though we study at different faculties, we see each other almost every day. 
+My best friend is the first to come and support me in any difficult situation. 
+We have a lot in common. We both do sports regularly. 
+That's because we want to be strong and look handsome. 
+We really look very much alike. We have short dark hair, grey eyes and a sport figure. 
+We also have many similar features of character: we are merry, smart and active.
+
+As Yura is an easy going person, he can easily make friends with anyone He likes communicating with new people. 
+Yura likes travelling. We often visit new places, especially in summer. 
+We have already been to the Crimea, Poltava and Lvov. This year we plan to visit the Carpathian Mountains. 
+Yura's hobby is computer games. He can spend hours in the virtual world. 
+As for me, I like the Internet, where I find interesting information and make friends with people all over the world. 
+But my best friend lives in Ukraine. I am glad I have such a friend as Yura.