C++ Matrix-Chain-Order / Can't get desired output

#include <string>
#include <iostream>
#include <vector>
#include <iomanip>

using namespace std;

int main()
{
     double m[7][7]; //2d dimension array m
     int s[7][7]; //2d dimension array s
     int p[7] = {30,35,15,5,10,20,25}; //array p to store numbers

     int j;
     double q;

     int n = 5;

    for(int i = 1; i != n; ++i) //initialize m[1][1], m[2][2], ... to zero
        m[i][i] = 0;
    for(int l = 2; l != n; ++l) // performing the algorithm 
    {
        for(int i = 1; i != (n-l+1); ++i)
        {
            j = i + (l-1);
            m[i][j] = numeric_limits<double>::max(); // find the max
            for(int k = i; k != (j-1); ++k)
            {
                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;
                }
            }
        }
    }

Test below:

    for(int i = 0; i != 4; ++i)
    {
        for(int j = 0; j != 4; ++j)
        {
            // print the m[i][j] to test the output
            cout << "m[" << i << "][" << j << "] " << " = " << m[i][j] << endl;;
        }
    }
}

I'm doing a matrix chain order, the output(my test case) should have values after performing the algorithm. But it's all zero like the picture. For example, m1[2] should be 30*35*15 = 15750.