Page 113 - Computer science 868 Class 12
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3.5.5 Algorithms on Matrix
Problem 14: Write an algorithm to calculate the sum of diagonals of a square matrix of a given size.
Note: The program already covered in the Array chapter of this book.
Step 1: Start.
Step 2: Initialise diagonal_one and diagonal_two to 0.
Step 3: Initialise i to 0.
Step 4: Repeat Step 5 to Step 12 while i < size.
Step 5: Initialise j to 0.
Step 6: Repeat Step 7 to Step 11 while j < size.
Step 7: If i = j then go to Step 8, else go to Step 9.
Step 8: Add array[i][j] to diagonal_one and store the result in diagonal_one.
Step 9: If i + j = size - 1 then go to Step 10 else go to Step 11.
Step 10: Add array[i][j] to diagonal_two and store the result in diagonal_two.
Step 11: Increment j by 1.
Step 12: Increment i by 1.
Step 13: Display diagonal_one and diagonal_two.
Step 14: Stop.
Problem 15: Write an algorithm to multiply two matrices and display the product matrix.
Note: The program already covered in the Array chapter of this book.
Step 1: Start.
Step 2: If column_first = row_second then go to Step 3, else go to Step 15.
Matrix multiplication
1 2 × 5 6 = 1*5 + 2*0 1*6 + 2*7 = 5 20
3 4 0 7 3*5 + 4*0 3*6 + 4*7 15 46
Step 3: Initialise i to 0.
Step 4: Repeat Step 5 to Step 13 while i < row_first.
Step 5: Initialise j to 0.
Step 6: Repeat Step 7 to Step 12 while i < column_second.
Step 7: Initialise product[i][j] to 0.
Step 8: Initialise k to 0.
111
Implementation of Algorithms to Solve Problems 111

