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 (r Range) length() int {
	return r.end - r.start + 1
}

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[r.start].r, matrices[r.end].c}, v
	}
	if r.length() == 0 {
		panic("must not be empty")
	} else if r.length() == 1 {
		return matrices[r.start], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < r.length()-1; i++ {
		formerRange := Range{r.start, r.start + i}
		latterRange := Range{r.start + i + 1, r.end}
		matF, countF := calcMinMatrixChainMultiplication(matrices, formerRange, memo)
		matL, countL := calcMinMatrixChainMultiplication(matrices, latterRange, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[r.start].r, matrices[r.end].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 <iostream>
#include <vector>
#include <algorithm>

#define INF (int)1e+9
using namespace std;

void dumpmat(vector<vector<int> >& a,int n){

  for( int i=1; i<=n; i++ ){
    for( int j=1; j<=n; j++ ){
      cout << a[i][j] << " ";
    }
    cout << "\n";
  }
  cout << "\n";
}

int main(){

  int n; cin >> n;
  vector<int> p(n+1);
  for(int i=0; i<n; i++) cin >> p[i] >> p[i+1];

  vector<vector<int> > m(n+1, vector<int>(n+1,INF));
  // dp[i][k] : i (0 <= i <= n-1)???????????? k (1 <= k <= n) ??????????????????????°????
  /*
  for(int i=0; i<=n; i++) m[i][1] = 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] + p[i-1]*p[k]*p[j]);
      }
      dumpmat(dp,n);
    }
  } 
  cout << dp[1][n] << endl;
*/
  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]);
      }
      //      dumpmat(m,n);
    }
  }

  cout << m[1][n] << endl;
  return 0; 
}

C++: #include <stdio.h>
#include <iostream>
#include <utility>
#include <algorithm>
#include <math.h>
#include <vector>
using namespace std;
#define inf pow(100, 4) + 1

int dp[100][100] = {};
int n;
int getMCM(int r[], int c[])
{
    int k;
    for (int i = 1; i < n; i++)
    {
        k = 0;
        for (int j = i; j < n; j++)
        {
            dp[k][j] = inf;
            for (int l = k; l < j; l++)
            {
                dp[k][j] = min(dp[k][j], dp[k][l] + dp[l + 1][j] + r[k] * c[j] * c[l]);
            }
            k++;
        }
    }
    return dp[0][n - 1];
}

int main()
{
    cin >> n;
    int r[n], c[n];
    for (int i = 0; i < n; i++)
        cin >> r[i] >> c[i];

    cout << getMCM(r, c) << "\n";
    return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;
static const int N=100;

int main(){
  int n,p[N+1],m[N+1][N+1];
  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;
}

C++: #include<bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i) 
#define PI acos(-1)

using namespace std;
using ll = long long;
using P = pair<int, int>;
using LP = pair<ll, ll>;

template<class T> inline bool chmax(T& a, T b) {if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) {if (a > b) { a = b; return true; } return false; }

ll dpRec(int l, int r, vector<vector<ll>>& dp, vector<LP> rc) {
    if (dp[l][r] != INT_MAX) return dp[l][r];
    if (r - l == 1) {
        dp[l][r] = 0;
        return 0;
    }
    for (int i = l + 1; i < r; ++i) {
        chmin(dp[l][r], dpRec(l, i, dp, rc) + dpRec(i, r, dp, rc) + rc[l].first * rc[i].first * rc[r - 1].second);
    }
    return dp[l][r];
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin>>n;
    vector<LP> rc(n);
    rep(i, n) cin>>rc[i].first>>rc[i].second;

    vector<vector<ll>> dp(n + 1, vector<ll>(n + 1, INT_MAX));
    // for (int i = 2; i < n + 1; ++i) {           // 行列をi個選ぶ
    //     for (int j = 0; j < n - i + 1; ++j) {   // j番目の行列以降から
    //         for (int k = 1; k < i; ++k) {       // j番目からk個までとそれ以降の積
    //             chmin(dp[i][j], dp[k][j] + dp[i - k][j + k] + rc[j].first * rc[j + k].first * rc[j + i].first);
    //         }
    //     }
    // }
    cout<<dpRec(0, n, dp, rc)<<endl;
}

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

static const int N = 100;

int main(){
  int n,p[N+1],m[N+1][N+1];
  
  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 j=2;j<=n;j++){
    for(int i=1;i<= n-j+1;i++){
      int l = i+j-1;
      m[i][l]=(1 << 21);
      for(int k=i;k<= l-1;k++){
	m[i][l]=min(m[i][l],m[i][k]+m[k+1][l]+p[i-1]*p[k]*p[l]);
      }
    }
  }

  cout << m[1][n] << endl;

  return 0;
}

C++: #include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <complex>
#include <ctime>
#include <cstdlib>

using namespace std;

inline int to_int(string s) {int v; istringstream sin(s); sin >> v; return v;}
template<class T> inline string to_str(T x) {ostringstream sout; sout << x; return sout.str();}

typedef long long ll;
typedef pair<int, int> P;
const int INF = 1<<22;

// dp[i][j] := [i , j]??????????????????????????則???????????????????属???即????????属
// |(4*5   (5*3)  3*2)|  2*1
int main()
{
	int n, dp[128][128], r[128];
	P T[128];

	cin >> n;

	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
		 	dp[i][j] = INF;
		}
	}
	/*
	for(int i = 0; i < n; i++)
	{
		dp[i][i] = 0;
	}
	*/
	for(int i = 0; i < n; i++)
	{
		cin >> T[i].first >> T[i].second;
		dp[i][i] = 0;
	}
	/*
	r[0] = T[0].first;
	for(int i = 0; i < n; i++)
	{
		r[i+1] = T[i].second;
	}
	*/
	/*
	for(int i = 0; i <= n; i++)
	{
		cout << r[i] << endl
	}
	*/
	/*
	for(int l = 1; l < n; l++)
	{
		for(int i = 0; i < n-l; i++)
		{ 
			int j = i + l;
			for(int k = 1; k <= l; k++)
			{
				dp[i][j] = std::min(dp[i][j], dp[i][i + k - 1] + dp[i + k][j] + T[i].first*T[i + k].first*T[j].second); //r[j]*r[k]*r[i+j+1]);
			}
		}
	}
*/
	for(int i = 1; i < n; i++)
	{
		for(int j = 0; j < n-i; j++)
		{ 
			for(int k = 1; k <= i; k++)
			{
				dp[i][j] = std::min(dp[i][j], dp[k-1][j] + dp[i-k][j+k] + T[j].first*T[j + k].first*T[j + i].second); //r[j]*r[k]*r[i+j+1]);
				printf("%3d : %3d : %3d => %3d\n", i, j, k, dp[i][j]);
				//puts("run");
			}
		}
	}

	/*
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			printf("%10d ",dp[i][j]);
		}
		puts("");
	}
	*/

	cout << dp[0][n - 1] << endl;
}