Upload files to 'Exercise 10 - Matrix Multiplication (Week 11)'

Exercise 10 - Matrix Multiplication (Week 11)/Ex10.txt

@@ -0,0 +1,21 @@
+20	
+25	97
+97	5
+5	79
+79	41
+41	67
+67	63
+63	7
+7	88
+88	96
+96	39
+39	3
+3	4
+4	73
+73	97
+97	54
+54	29
+29	73
+73	93
+93	39
+39	68

Exercise 10 - Matrix Multiplication (Week 11)/ex10.c

@@ -0,0 +1,97 @@
+/* License: AGPLv3 or later. https://www.gnu.org/licenses/licenses.html
+ * 
+* Exercise 10 - Matrix Multiplication (Week 11)
+* Name : Manish
+* Student Login : *****
+*
+* Compile as:
+* $ gcc -Wall -std=c11 -o ex10 ex10.c
+*/
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+int* array = NULL;
+int* memo = NULL;
+int matrices = 0;
+
+int best(int i, int j);
+int min(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 ", &matrices) != EOF)
+    {;
+        array = malloc(sizeof(int) * (matrices + 1));
+        memo = malloc(sizeof(int) * matrices);
+        if (matrices > 0 && (array == NULL || memo == NULL))
+        {
+            fprintf(stderr, " Failed to allocate memory \n");
+            return 1;
+        }
+    }
+
+    // Read and push matrix dimensions to array
+    fscanf(file, " %d %d ", &array[0], &array[1]); // first matrix dimensions
+    int row ;
+    int col;
+    for (int i = 1; i < matrices; i++)
+    {
+        fscanf(file, " %d %d ", &row, &col);
+        // row of current matrix must match column of previous matrix
+        if (row == array[i])
+            array[i] = row;
+        else
+        {
+            fprintf(
+                stderr,
+                " Rows , columns mismatch , multiplication not possible \n"
+            );
+            exit(1);
+        }
+        array[i + 1] = col;
+    }
+    fclose(file);
+    // Initialize memorization array elements to 0 s
+    for ( int i =0; i < matrices * matrices ; i ++)
+        memo[i] = 0;
+    
+    // Compute and print minimum multiplications needed
+    printf ( "%d\n", best(1, matrices));
+
+    free ( array ) ;
+
+    return 0;
+}
+
+int best(int i, int j)
+{
+    if (i == j)
+        return 0;
+    if (memo[matrices * i + j] != 0)
+        return memo[matrices * i + j];
+    int b = INT_MAX;
+    for (int k = i; k < j; k++)
+        b = min(b, (array[i-1] * array[j] * array[k]) + best(i,  k) + best(k+1, j));
+    memo[matrices * i + j] = b;
+    return b;
+}
+
+int min(int i, int j)
+{
+    return i < j ? i : j;
+}

Exercise 10 - Matrix Multiplication (Week 11)/makefile

@@ -0,0 +1,2 @@
+ex10:	ex10.c
+	gcc -Wall -std=c11 -o ex10 ex10.c