Code:
#include stdio.h
#include limits.h
#include iostream
using namespace std;
// Matrix Ai has dimension p[i-1] x p[i] for i = 1..n
int MatrixChainOrder(int p[], int n)
{
/* For simplicity of the program, one extra row and one extra column are
allocated in m[][]. 0th row and 0th column of m[][] are not used */
int m[n][n];
int s[n][n];
int i, j, k, L, q;
/* m[i,j] = Minimum number of scalar multiplications needed to compute
the matrix A[i]A[i+1]...A[j] = A[i..j] where dimention of A[i] is
p[i-1] x p[i] */
// cost is zero when multiplying one matrix.
for (i = 1; i < n; i++)
m[i][i] = 0;
// L is chain length.
for (L = 2; L < n; L++)
{
for (i = 1; i <= n - L + 1; i++)
{
j = i + L - 1;
m[i][j] = INT_MAX;
for (k = i; k <= j - 1; k++)
{
// q = cost/scalar multiplications
q = m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j];
if (q < m[i][j])
{
m[i][j] = q;
s[i][j] = k;
}
}
}
}
return m[1][n - 1];
}
int main()
{
cout
<< "Enter the array p[], which represents the chain of matrices such that the ith matrix Ai is of dimension p[i-1] x p[i]";
cout << "Enter the total length:";
int n;
cin >> n;
int array[n];
cout << "Enter the dimensions: ";
for (int var = 0; var < n; ++var)
{
cin >> array[var];
}
cout << "Minimum number of multiplications is: " << MatrixChainOrder(array,
n);
return 0;
}
Output:
Enter the array p[], which represents the chain of matrices such that the ith matrix Ai is of dimension p[i-1] x p[i]Enter the total length:4
Enter the dimensions: 2 4 3 5
Minimum number of multiplications is: 54
More C++ Programs:
