Implementation of Matrix Chain Multiplication using Dynamic Programming in Java

We’ve discussed Matrix Chain Multiplication using Dynamic Programming in our last article ver clearly. In this article, we are going to implement it in Java.

Pseudocode

// Matrix A[i] has dimension dims[i-1] x dims[i] for i = 1..n
MatrixChainOrder(int dims[])
{
    // length[dims] = n + 1
    n = dims.length - 1;
    // m[i,j] = Minimum number of scalar multiplications (i.e., cost)
    // needed to compute the matrix A[i]A[i+1]...A[j] = A[i..j]
    // The cost is zero when multiplying one matrix
    for (i = 1; i <= n; i++)
        m[i, i] = 0;
for (len = 2; len <= n; len++) { // Subsequence lengths
        for (i = 1; i <= n - len + 1; i++) {
            j = i + len - 1;
            m[i, j] = MAXINT;
            for (k = i; k <= j - 1; k++) {
                cost = m[i, k] + m[k+1, j] + dims[i-1]*dims[k]*dims[j];
                if (cost < m[i, j]) {
                    m[i, j] = cost;
                    s[i, j] = k; // Index of the subsequence split that achieved minimal cost
                }
            }
        }
    }
}

Let’s implement the way we discussed in our previous article.

1. Matrix.java

public class Matrix {
    int row;
    int col;
 
    public Matrix(int row, int col) {
        this.row = row;
        this.col = col;
    }
}

2. MatrixChain.java

public class MatrixChain {…