diff --git a/lab4/src/find_min_max.c b/lab4/src/find_min_max.c
new file mode 100755
index 000000000..f3be42e06
--- /dev/null
+++ b/lab4/src/find_min_max.c
@@ -0,0 +1,18 @@
+#include "find_min_max.h"
+
+#include <limits.h>
+
+struct MinMax GetMinMax(int *array, unsigned int begin, unsigned int end) {
+ struct MinMax min_max;
+ min_max.min = INT_MAX;
+ min_max.max = INT_MIN;
+
+ int i;
+ for (i = begin; i <=end; i++){
+ if (min_max.min > array[i])
+ min_max.min = array[i];
+ if(min_max.max < array[i])
+ min_max.max = array[i];
+ }
+ return min_max;
+}
diff --git a/lab4/src/find_min_max.h b/lab4/src/find_min_max.h
new file mode 100755
index 000000000..07892028c
--- /dev/null
+++ b/lab4/src/find_min_max.h
@@ -0,0 +1,8 @@
+#ifndef FIND_MIN_MAX_H
+#define FIND_MIN_MAX_H
+
+#include "utils.h"
+
+struct MinMax GetMinMax(int *array, unsigned int begin, unsigned int end);
+
+#endif
diff --git a/lab4/src/parallel_min_max.c b/lab4/src/parallel_min_max.c
new file mode 100755
index 000000000..1fb59904f
--- /dev/null
+++ b/lab4/src/parallel_min_max.c
@@ -0,0 +1,230 @@
+#include <ctype.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <getopt.h>
+
+#include <signal.h>
+
+#include "find_min_max.h"
+#include "utils.h"
+
+void myalarm(){
+ kill(0, SIGKILL);
+}
+
+int main(int argc, char **argv) {
+ int i=0;
+ int seed = -1;
+ int array_size = -1;
+ int pnum = -1;
+ bool with_files = false;
+ int timeout = 0;
+
+ while (true) {
+ int current_optind = optind ? optind : 1;
+
+ static struct option options[] = {{"seed", required_argument, 0, 0},
+ {"array_size", required_argument, 0, 0},
+ {"pnum", required_argument, 0, 0},
+ {"by_files", no_argument, 0, 'f'},
+ {"timeout", required_argument, 0, 0},
+ {0, 0, 0, 0}};
+
+ int option_index = 0;
+ int c = getopt_long(argc, argv, "f", options, &option_index);
+
+ if (c == -1) break;
+
+ switch (c) {
+ case 0:
+ switch (option_index) {
+ case 0:
+ seed = atoi(optarg);
+ // your code here
+ // error handling
+ if (seed <= 0) {
+ printf("seed is a positive number\n");
+ return 1;
+ }
+ break;
+ case 1:
+ array_size = atoi(optarg);
+ // your code here
+ // error handling
+ if (array_size <= 0) {
+ printf("array_size is a positive number\n");
+ return 1;
+ }
+ break;
+ case 2:
+ pnum = atoi(optarg);
+ // your code here
+ // error handling
+ if (pnum <= 0) {
+ printf("pnum is a positive number\n");
+ return 1;
+ }
+ break;
+ case 3:
+ with_files = true;
+ break;
+ case 4:
+ timeout = atoi(optarg);
+ if (timeout < 0) {
+ printf("timeout is a positive number\n");
+ return 1;
+ }
+ break;
+
+ default:
+ printf("Index %d is out of options\n", option_index);
+ }
+ break;
+ case 'f':
+ with_files = true;
+ break;
+
+ case '?':
+ break;
+
+ default:
+ printf("getopt returned character code 0%o?\n", c);
+ }
+ }
+
+ if (optind < argc) {
+ printf("Has at least one no option argument\n");
+ return 1;
+ }
+
+ if (seed == -1 || array_size == -1 || pnum == -1) {
+ printf("Usage: %s --seed \"num\" --array_size \"num\" --pnum \"num\" \n",
+ argv[0]);
+ return 1;
+ }
+
+ int *array = malloc(sizeof(int) * array_size);
+ GenerateArray(array, array_size, seed);
+
+ int active_child_processes = 0;
+
+ struct timeval start_time;
+ gettimeofday(&start_time, NULL);
+ int file_pipe_min[2];
+ int file_pipe_max[2];
+ if (pipe(file_pipe_min)<0)
+ {exit(0);}
+ if (pipe(file_pipe_max)<0)
+ {exit(0);}
+
+ for (i = 0; i < pnum; i++) {
+ pid_t child_pid = fork();
+ if (child_pid >= 0) {
+ // successful fork
+ active_child_processes += 1;
+ if (child_pid == 0) {
+ // child process
+ // parallel somehow
+ sleep(10);
+ struct MinMax min_max = GetMinMax(array,0,array_size);
+ if (with_files) {
+ FILE *f;
+ f=fopen("min_max.txt","w");
+ char buf[33];
+ sprintf(buf,"%d",min_max.min);
+ fprintf(f,buf);
+ fprintf(f,"\n");
+ sprintf(buf,"%d",min_max.max);
+ fprintf(f,buf);
+ fprintf(f,"\n");
+ } else {
+ // use pipe here
+ char buf[256];
+ sprintf(buf,"%d",min_max.min);
+ write(file_pipe_min[1],buf,30);
+ //printf("%s\n", buf);
+ sprintf(buf,"%d",min_max.max);
+ write(file_pipe_max[1],buf,30);
+ //printf("%s\n", buf);
+ }
+ return 0;
+ }
+
+ } else {
+ printf("Fork failed!\n");
+ return 1;
+ }
+ }
+ if(timeout > 0){
+ signal(14, myalarm);
+ alarm(timeout);
+ }
+
+ int status;
+ while (active_child_processes > 0) {
+ // your code here
+ waitpid(-1, &status, WNOHANG);
+ active_child_processes -= 1;
+ }
+
+ struct MinMax min_max;
+ min_max.min = INT_MAX;
+ min_max.max = INT_MIN;
+
+ for (i = 0; i < pnum; i++) {
+ int min = INT_MAX;
+ int max = INT_MIN;
+
+ if (with_files) {
+ FILE *f = fopen("min_max.txt","r");
+ char buf[256];
+ int a;
+ fscanf(f,"%s",buf);
+ //printf("%s\n",buf);
+ a=atoi(buf);
+ if (min>a) min=a;
+ fscanf(f,"%s",buf);
+ //printf("%s\n",buf);
+ a=atoi(buf);
+ if (max<a) max=a;
+ } else {
+ // read from pipes
+ char buf[256];
+ int a;
+ read(file_pipe_min[0],buf,30);
+ //printf("%s\n",buf);
+ a=atoi(buf);
+ if (min>a) min=a;
+ read(file_pipe_max[0],buf,30);
+ //printf("\n%s\n",buf);
+ a=atoi(buf);
+ if (max<a) max=a;
+ }
+
+ if (min < min_max.min) min_max.min = min;
+ if (max > min_max.max) min_max.max = max;
+ }
+
+ struct timeval finish_time;
+ gettimeofday(&finish_time, NULL);
+
+ double elapsed_time = (finish_time.tv_sec - start_time.tv_sec) * 1000.0;
+ elapsed_time += (finish_time.tv_usec - start_time.tv_usec) / 1000.0;
+
+ free(array);
+
+ printf("Min: %d\n", min_max.min);
+ printf("Max: %d\n", min_max.max);
+ printf("Elapsed time: %fms\n", elapsed_time);
+ fflush(NULL);
+ return 0;
+}