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>
using namespace std;

int MCM(int molCol[], int matNum) {
	int DP_memory[100+1][100+1];

	//?????????????????????
	for (int i = 1; i <= matNum; i++)
		DP_memory[i][i] = 0;

	for (int l = 2; l <= matNum; l++) { //???????????¨????????????(i = 2??????2??????????????§????????????????°???????????±???????)
		for (int i = 1; i <= matNum - l + 1; i++) { //?????????????????§????°???????
			int j = i + l - 1; //??????????????§?????§??????
			DP_memory[i][j] = (1 << 30); //??????????????????????????§?????????(????°???????????±?????????????)
			for (int k = i; k < j; k++) //i??¨j????????§????????????????????????????????´???
				DP_memory[i][j] = DP_memory[i][j] < (DP_memory[i][k] + DP_memory[k + 1][j] + molCol[i - 1] * molCol[k] * molCol[j])
					? DP_memory[i][j] : (DP_memory[i][k] + DP_memory[k + 1][j] + molCol[i - 1] * molCol[k] * molCol[j]);
		}
	}

	return DP_memory[1][matNum];
}

int main() {
	int matNum;
	int molCol[200+1];
	cin >> matNum;
	for (int i = 1; i <= matNum; i++) {
		cin >> molCol[i - 1] >> molCol[i];
	}

	int answer = MCM(molCol, matNum);

	cout << answer << endl;
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#define INT_MAX 100000000
using namespace std;
int index;
int mm[1000][1000];
int mine = INT_MAX;
 
void solve(int p[]){
  int n = index-1,j,q;
  for(int i=1;i<=n;i++)mm[i][i]=0;
  for(int l=2;l<=n;l++){
    for(int i=1;i<=n-l+1;i++){
      j = i+l-1;
      mm[i][j] = INT_MAX;
      for(int k=i;k<=j-1;k++){
    q = mm[i][k] + mm[k+1][j] + p[i-1]*p[k]*p[j];
    if(q<mm[i][j]){
      mm[i][j] = q;
        
    }
 
      }
    }
  }
 
 
 
 
}
 
int main(){
  int p[1000],a,b;
  scanf("%d",&index);
  //for(int i=0;i<=index;i++)for(int j=0;j<=n;j++)mm[i][j] = INT_MAX;
  for(int i=0;i<index;i++){
    scanf("%d %d",&a,&b);
    p[i] = a;
    if(i == index-1)p[i+1] = b;
  }
 
  index = index+1;
  solve(p);
  
  printf("%d\n",mm[1][index-1]);
  return 0;
}

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

int n;
int m[101][101];
int p[101];

int main() {
    cin >> n;
    int count = n - 1, temp, i, j, k;

    cin >> p[0] >> p[1];
    for ( i = 2; i <= n; i++ ) {
        cin >> temp >> p[i];
    }

    for ( i = 1; i <= n; i++ ) m[i][i] = 0;

    for ( i = 1; i <= n-1; i++ ) {
        for ( j = 1; j <= n - i; j++ ) {
            temp = p[j - 1] * p[j] * p[j + i] + m[j + 1][j + i] + m[j][j];
            for ( k = j + 2; k <= i + j; k++ ) {
                temp = min(temp, p[j - 1] * p[k - 1] * p [j + i] + m[k][j + i] + m[j][k - 1]);
            }
            m[j][j + i] = temp;
        }
    }

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

    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <climits>
#define range(i, a, b) for(int i = (a); i <= (int)(b); i++)
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define repR(i, n) for(int i = (n) - 1; i > -1; i--)
#define rep1(i, n) for(int i = 1; i < (int)(n + 1); i++)
#define rep1R(i, n) for(int i = (n); i > 0; i--)
using namespace std;

int n;
int m[110][110];
int p[110];

int matrixChainMultiplication() {
  rep1(i, n) m[i][i] = 0;

  range(l, 2, n) {
    rep1(i, n - 1 + 1) {
      int j = i + l - 1;
      m[i][j] = INT_MAX;
      range(k, i, j - 1) {
        m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
      }
    }
  }
  return m[1][n];
}

int main() {
  cin >> n;
  rep1(i, n) {
    cin >> p[i - 1] >> p[i];
  }
  cout << matrixChainMultiplication() << endl;
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
const int INF = (1 << 29);

struct Matrix
{
  int r, c;
};

vector<Matrix> M;

int rec(vector<vector<int>> &dp, int top, int bottom)
{
  if (dp.at(top).at(bottom) != INF)
  {
    return dp.at(top).at(bottom);
  }
  if (top == bottom)
  {
    dp.at(top).at(bottom) = 0;
    return 0;
  }
  for (int mid = top; mid < bottom; mid++)
  {
    dp.at(top).at(bottom) = min(dp.at(top).at(bottom), rec(dp, top, mid) + rec(dp, mid + 1, bottom) + M.at(top).r * M.at(mid).c * M.at(bottom).c);
  }
  return dp.at(top).at(bottom);
}

int main()
{
  int n;
  cin >> n;
  M.resize(n);
  for (int i = 0; i < n; i++)
  {
    int r, c;
    cin >> r >> c;
    M.at(i) = Matrix{r, c};
  }
  vector<vector<int>> dp(n + 1, vector<int>(n + 1, INF));
  cout << rec(dp, 0, n - 1) << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
using ll = long long;
using P = pair<int, int>;

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>
using namespace std;
#define N 100
#define INF 1<<25
int n,p[N+1],m[N+1][N+1];
int matrixchainmultiplication(){
  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]=INF;
      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]);
      }
    }
  }
  return m[1][n];
}
int main(){
  cin>>n;
  for(int i=0;i<n;i++) cin>>p[i]>>p[i+1];
  cout<<matrixchainmultiplication()<<endl;
  return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for(ll i = 0; i < (n); i++)
#define roop(i, a, n) for(ll i = (a); i < (n); i++)
using namespace std;
using ll = long long;

int main(){
    ll n; cin >> n;
    ll dp[n+1][n+1];
    ll a[n+1];
    roop(i, 1, n+1) cin >> a[i - 1] >> a[i];

    roop(i, 1, n+1) dp[i][i] = 0;
    roop(l, 2, n+1){
        roop(i, 1, n-l+2){
            ll j = i + l - 1;
            dp[i][j] = INT_MAX;
            roop(k, i, j) dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + a[i-1]*a[k]*a[j]);
        }
    }
    cout << dp[1][n] << endl;

    return 0;
}