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<bits/stdc++.h>
using namespace std;

#define reps(i, n, m) for (int i = (int) (n); i < (int) (m); i++)
#define rep(i, n) reps(i, 0, (n))
#define all(v) (v).begin(), (v).end()

const int inf = 1e9+100;
vector<vector<int>> dp;
vector<int> a, b;

int dfs(int l, int r) {
    int& res = dp[l][r];
    if (res != inf) return res;
    if (r - l == 1) return res = 0;
    reps(i, l+1, r) {
        int t = dfs(l, i) + dfs(i, r) + a[l] * a[i] * b[r-1];
        res = min(res, t);
    }
    return res;
}

int main() {
    int n; cin >> n;
    a.resize(n); b.resize(n);
    rep(i, n) cin >> a[i] >> b[i];
    dp.resize(n+1, vector<int>(n+1, inf));
    cout << dfs(0, n) << endl;
}

C++: #include <algorithm>
#include <complex>
#include <cstdlib>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;
#define SAY_YES cout << "YES" << endl;
#define SAY_Yes cout << "Yes" << endl;
#define SAY_NO cout << "NO" << endl;
#define SAY_No cout << "No" << endl;
#define IFYES(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "YES" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "NO" << endl;  \
    }
#define IFYes(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "Yes" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "No" << endl;  \
    }
#define IFyes(TRUE_OR_FALSE)   \
    if (TRUE_OR_FALSE)         \
    {                          \
        cout << "yes" << endl; \
    }                          \
    else                       \
    {                          \
        cout << "no" << endl;  \
    }
#define DEBUG_OUTPUT_ARRAY(XXX, ONE)                            \
    for (int i = 0; i < (ONE); i++)                             \
    {                                                           \
        cout << "DEBUG: i = " << i << " -> " << XXX[i] << endl; \
    }
#define DEBUG_OUTPUT_ARRAY2(XXX, ONE, TWO)                             \
    for (int i = 0; i < (ONE); i++)                                    \
    {                                                                  \
        cout << "<<< i = " << i << " >>>" << endl;                     \
        for (int j = 0; j < (TWO); j++)                                \
        {                                                              \
            cout << "DEBUG: j = " << j << " -> " << XXX[i][j] << endl; \
        }                                                              \
    }
#define DEBUG_OUTPUT_ARRAY2_BOX(XXX, ONE, TWO) \
    for (int i = 0; i < (ONE); i++)            \
    {                                          \
        cout << i << "  ";                     \
        for (int j = 0; j < (TWO); j++)        \
        {                                      \
            cout << XXX[i][j] << " ";          \
        }                                      \
        cout << endl;                          \
    }

typedef pair<long long int, long long int> pll;


const long long int mod = 1000000007;
const long long int INF = 19999999999999;

long long int n,r[105],c[105],dp[105][105]={};
int main()
{
    cout << fixed << setprecision(18);
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>r[i]>>c[i];
    }
    for(long long int i = 0; i <= n; i++){

        for(long long int j = 0; j <= n; j++){
            dp[i][j]=INF;
        }
    }
    for(long long int i = 0; i <= n; i++){
        dp[i][i]=0;
    }
    for(long long int i = 0; i <= n-1; i++){
        dp[i][i+1]=0;
    }
    for(long long int i = 0; i <= n-2; i++){
        dp[i][i+2]=r[i]*r[i+1]*c[i+1];
    }

    for(long long int i = 3; i <= n ; i++){
        for(long long int j = 0; j <= n-i ; j++){
            for(long long int k = j; k <=j+i; k++){
                dp[j][j+i] = min(dp[j][j+i],dp[j][k]+dp[k][j+i]+r[j]*r[k]*c[j+i-1]);
            }
        }
    }
    cout<<dp[0][n]<<endl;
}

C++: #include <iostream>
#include <algorithm>

#define N 100

using namespace std;

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 <stdlib.h>
#include <stdio.h>

int MCM(int n){
int i,j,k,l,m[101][101],p[101],x;

for(i=1;i<=n;i++)m[i][i]=0;
for(l=2;l<=n;l++){
    for(i=1;i<=n-l+1;i++){
        j=i+l-1;
     m[i][j]=10000000;
        for(k=i;k<=j;k++){
            x=m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j];
            if(m[i][j]>x)m[i][j]=x;
            }
        }
    }
return m[i-1][j];
}

int main(){

int i,n,m[101];

scanf("%d",&n);
for(i=0;i<n;i++){
    scanf("%d %d",&m[i],&m[i+1]);
   }
printf("%d\n",MCM(n));
return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define int long long
int dp[111][111];
signed main(){
  int n;
  cin>>n;
  int r[n],c[n];
  for(int i=0;i<n;i++) cin>>r[i]>>c[i];
  int INF=1LL<<55LL;
  for(int i=0;i<111;i++) fill_n(dp[i],111,INF);
  for(int i=0;i<n;i++) dp[i][i+1]=0;
  for(int i=2;i<=n;i++)
    for(int j=0;j<=n-i;j++)
      for(int k=1;k<i;k++)
	dp[j][j+i]=min(dp[j][j+i],dp[j][j+k]+dp[j+k][j+i]+(r[j]*r[j+k]*c[j+i-1]));
  cout<<dp[0][n]<<endl;
  return 0;
}