Upload files to 'Exercise 8 - Dynamic Stack (Week 9)'

Exercise 8 - Dynamic Stack (Week 9)/Ex8.txt

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+2
+push 1
+push 1
+push 1
+push 1
+push 1
+pop
+pop
+push 1

Exercise 8 - Dynamic Stack (Week 9)/ex8.c

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+/* License: AGPLv3 or later. https://www.gnu.org/licenses/licenses.html
+ * 
+ * Exercise 8 - Dynamic Stack (Week 9)
+ * Name: Manish
+ * Student Login: *****
+ * 
+ * Compile as:
+ * $ gcc -std=c11 -Wall -o ex8 ex8.c
+ */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int* stack = NULL;
+int index = -1;
+int size = 0;
+
+void push(int n);
+int pop();
+int top();
+bool isEmpty();
+int max(int i, int j);
+
+int main(void)
+{
+    printf("Enter file name: ");
+    // Assuming filename/file path will not be longer than 256 characters
+    char filename[257];
+    scanf("%s", filename);
+
+    FILE* file = fopen(filename, "r");
+    if (!file)
+    {
+        perror(filename);
+        exit(EXIT_FAILURE);
+    }
+
+    if (fscanf(file, " %d ", &size) != EOF)
+    {
+        stack = malloc(sizeof(int) * size);
+        if (size > 0 && stack == NULL)
+        {
+            fprintf(stderr, "Failed to allocate memory\n");
+            return 1;
+        }
+    }
+
+    // Read and push integers to stack
+    char instruction[5];
+    int n;
+    while (fscanf(file, " %4s ", instruction) != EOF)
+    {
+        if (strcmp("push", instruction) == 0)
+        {
+            // whitespaces around to skip them inc. newlines
+            if (fscanf(file, " %d ", &n) != EOF)
+                push(n);
+        }
+        else
+            n = pop();
+    }
+
+    printf("Stack contains %d entries.\n", index + 1);
+
+    fclose(file);
+    free(stack);
+
+    return 0;
+}
+
+void push(int n)
+{
+    if (index == size - 1)
+    {
+        // max() in case original size is 0
+        int new_size = max(size * 2, 1);
+        int* new_stack = malloc(sizeof(int) * new_size);
+        if (new_stack == NULL)
+        {
+            fprintf(
+                stderr,
+                "Failed to double stack from %d to %d. Not pushing %d.\n",
+                size,
+                new_size,
+                n);
+            return;
+        }
+        printf("Stack doubled from %d to %d.\n", size, new_size);
+        memcpy(new_stack, stack, size*sizeof(int));
+        free(stack);
+        stack = new_stack;
+        size = new_size;
+    }
+    stack[++index] = n;
+}
+
+int pop()
+{
+    if (isEmpty())
+    {
+        return -1;
+    }
+    return stack[index--];
+}
+
+bool isEmpty()
+{
+    return index < 0;
+}
+
+int max(int i, int j)
+{
+    return (i > j) ? i : j;
+}

Exercise 8 - Dynamic Stack (Week 9)/makefile

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+ex8:	ex8.c
+	gcc -Wall -std=c11 -o ex8 ex8.c