Go: package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, v
	}
	if len(matrices) == 0 {
		panic("must not be empty")
	} else if len(matrices) == 1 {
		return matrices[0], 0
	} else if len(matrices) == 2 {
		return calcMultiplication(matrices[0], matrices[1])
	}

	var minCount int = math.MaxInt32

	for i := 0; i < len(matrices)-1; i++ {
		formerMatrices := matrices[:i+1]
		latterMatrices := matrices[i+1:]
		matF, countF := calcMinMatrixChainMultiplication(formerMatrices, Range{0, i}, memo)
		matL, countL := calcMinMatrixChainMultiplication(latterMatrices, Range{i + 1, len(matrices) - 1}, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <bits/stdc++.h>
using namespace std;
const int64_t INF = (1 << 21);
const int64_t MAXN = 110;
int64_t DP[MAXN][MAXN];

int main()
{
  int64_t N;
  cin >> N;
  vector<int64_t> M(N + 1);
  for (int i = 1; i <= N; i++)
    cin >> M[i - 1] >> M[i];
  for (int i = 1; i <= N; i++)
    DP[i][i] = 0;
  for (int l = 2; l <= N; l++)
  {
    for (int i = 1; i <= N - l + 1; i++)
    {
      int j = i + l - 1;
      DP[i][j] = INF;
      for (int k = i; k <= j - 1; k++)
      {
        DP[i][j] = min(DP[i][j], DP[i][k] + DP[k + 1][j] + M.at(i - 1) * M.at(k) * M.at(j));
      }
    }
  }
  cout << DP[1][N] << endl;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;

int main() {
	int n,p[101],m[101][101];cin>>n;for(int i=1;i<=n;i++)cin>>p[i-1]>>p[i];
	for(int i=1;i<=n;i++)m[i][i]=0;
	for(int l=2;l<=n;l++)
	{
		for(int i=1;i<=n-l+1;i++)
		{
			int j=i+l-1;m[i][j]=1<<21;
			for(int k=i;k<=j-1;k++)m[i][j]=min(m[i][j],m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
		}
	}
	cout<<m[1][n]<<endl;
	return 0;
}