Upload files to 'Exercise 3 - Virtual Initialization (Week 4)'

Exercise 3 - Virtual Initialization (Week 4)/Ex3.txt

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+42 7
+93 9
+11 4
+-1 -1
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Exercise 3 - Virtual Initialization (Week 4)/ex3.c

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+/* License: AGPLv3 or later. https://www.gnu.org/licenses/licenses.html
+ * 
+ * Exercise 3 - Virtual Initialization (Week 4)
+ * Name: Manish
+ * Student Login: *****
+ * 
+ * Compile as:
+ * $ gcc -std=c11 -Wall -o ex3 ex3.c
+ * 
+ * Assumption: Where input is 0 indexed and not starting from 1
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int data[100];
+int forward[100];
+int backward[100];
+int valid_indexes = -1;
+
+
+int main(void)
+{
+    printf("Enter file name: ");
+    char filename[257];
+    // Assuming filename/file path won't be longer than 256 characters
+    scanf("%256s", filename);
+
+    FILE* file = fopen(filename, "r");
+    if (!file)
+    {
+        perror(filename);
+        exit(EXIT_FAILURE);
+    }
+
+    int what = -10;
+    int where = -10;
+    // Trailing whitespaces to consume all subsequent ' ', \t, \n, \r
+    /* NOTE: Not using file position checks to detect when stuck in a loop
+     * assuming input to be in exact format as specified
+     */
+    while (fscanf(file, " %d ", &what) != EOF
+            && fscanf(file, " %d ", &where) !=EOF)
+    {
+        if (what == -1 && where == -1)
+        {
+            break;
+        }
+        // Where/index cannot be less than 0
+        if (where < 0 || where >= 100)
+        {
+            fprintf(
+                stderr, 
+                "Where index is %d but arrays index is only up to 99. "
+                "Ignoring this input.\n",
+                where);
+            continue;
+        }
+        data[where] = what;
+        forward[++valid_indexes] = where;
+        backward[where] = valid_indexes;
+    }
+    
+    int probe;
+    // Trailing whitespace to consume all subsequent ' ', \t, \n, \r
+    while(fscanf(file, " %d ", &probe) != EOF)
+    {
+        if (probe == -1)
+        {
+            break;
+        }
+        // Probe/index cannot be less than 0
+        if (probe < 0 || probe >= 100)
+        {
+            printf("Position %d does not exist.\n",probe);
+            continue;
+        }
+        if (backward[probe] <= valid_indexes
+            && forward[backward[probe]] == probe)
+        {
+            printf(
+                "Position %d has been initialized to value %d.\n",
+                probe,
+                data[probe]
+            );
+        }
+        else
+        {
+            printf("Position %d has not been initialized.\n", probe);
+        }
+    }
+
+    fclose(file);
+    
+    return 0;
+}

Exercise 3 - Virtual Initialization (Week 4)/makefile

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+ex3:	ex3.c
+	gcc -std=c11 -Wall -o ex3 ex3.c