算法导论15章矩阵链实现(c++)

#include "stdafx.h"
#include <iostream>
#include <math.h>

using namespace std;

#define N 7
#define INFINITY 100000000;

int m[N-1][N-1];
int s[N-1][N-1];
void Matrix_chain_order (int p[])//特别容易搞错边界，这种写法不好
{
    for (int i = 0; i < N - 1; i++)
        m[i][i] = 0;
    for (int l = 2; l < N; l++)
        for (int i = 0; i < N - l; i++)
        {
            int j = i + l - 1;
            m[i][j] = INFINITY;
            for (int k = i; k < j; k++)
            {
                int q = m[i][k] + m[k+1][j] + p[i]*p[k+1]*p[j+1];
                if (q < m[i][j])
                {
                    m[i][j] = q;
                    s[i][j] = k;
                }
            }
        }    
    return;
}

void Print_optimal_parens (int i, int j)//打印输出最优
{
    if(i==j)
        cout<<"A["<<i<<"]";
    else
    {    cout<<"(";
        Print_optimal_parens (i,s[i][j]);
        Print_optimal_parens (s[i][j]+1,j);
        cout<<")";
    }
}
int main()
{
    int p[N] = {30, 35, 15, 5, 10, 20, 25};
    Matrix_chain_order (p);
    Print_optimal_parens (0,5);
    system("pause");
    return 0;
}