Assignment1_zhen

mm.c

@@ -0,0 +1,89 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <sys/wait.h>
+
+
+#define debug 0
+#define SUCCESS  0 //changed from 1 to 0
+#define FAILURE -1 //changed from 0 to -1
+
+
+// Comparison function for qsort()
+int numcmp (const void *a, const void *b) {
+    int x = *((int*) a);
+    int y = *((int*) b);
+    if (x > y) return 1;
+    if (x < y) return -1;
+    return 0;
+}
+
+float mean(int nums[], int size)	//mean function for calculation the mean of an array of float numbers
+{
+  	float sum=0;
+    for (int i = 0; i <=size-1; i++)
+    {
+		sum +=nums[i];
+    }
+
+   	return sum/size;
+}
+
+float median(int nums[], int size)	//median function for calculation the mean of an array of float numbers
+{
+  	if(size%2==0)return (nums[(size/2)-1]+nums[size/2])/2;	//if the array has an even number of integers, we calculate the mean of two numbers in the middle
+  	else return nums[size/2];
+}
+
+int main(int argc, char *argv[]) {
+
+    int i, length, *pt;
+
+    // Check for proper usage
+    if (argc < 2) {
+        fprintf(stderr, "%s: Aborting, not enough arguments.\n", argv[0]);
+        return (-1);
+    }
+
+    // Determine amount of numbers from argc
+    length = argc - 1;
+#if debug
+    fprintf(stderr, "%s: DEBUG: %d numbers were passed.\n", argv[0], length);
+#endif
+
+    // Allocate memory for array of number (and error check)
+    if ((pt = malloc(length * sizeof(int))) == NULL) {
+        fprintf(stderr, "%s: Could not allocate memory.\n", argv[0]);
+    }
+
+    // Read numbers into array
+    for (i = 0; i < length; i++) {
+        pt[i] = (int) strtol(argv[i+1], NULL, 10);
+    }
+
+    // Sort numbers
+    qsort(pt, length, sizeof(int), numcmp);
+
+    // Print out numbers
+    fprintf(stdout, "%s: Sorted output is: \n", argv[0]);
+    for (i=0; i<length; i++) {
+        fprintf(stdout, "%d ", pt[i]);
+    }
+    fprintf(stdout, "\n%s: FIN. \n", argv[0]);
+
+	//fork added below, copied from the first lab
+	  int rc = fork(); //slice off another process
+	  if (rc == -1) { //fork() returns -1, exit with error message.
+		fprintf(stdout, "Fork failed");
+		exit(FAILURE);
+	  } else if (rc == 0) { //when fork() returns 0, exit with success message.
+		float medianV = median(pt,length);	//child calls median
+		fprintf(stdout, "The median value is: %.2f, it's child process. \n", medianV);
+	  } else { //when fork() returns others nums, create new child 
+		wait(NULL); //is child finished?
+		float meanV = mean(pt,length);	//parent calls mean
+		fprintf(stdout, "The mean value is: %.2f, it's parent process. \n", meanV);
+	  }
+	  return SUCCESS;
+}