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 <algorithm>
#include <iostream>
#include <vector>

#define INF 1000000007

int main(){
    int n;
    std::cin >> n;

    std::vector<int> row(n), col(n);
    for(int i = 0; i < n; ++i){
        std::cin >> row.at(i) >> col.at(i);
    }

    // consider a n * n dp matrix with INF as the minimum value is the interest of this exercise
    std::vector<std::vector<int>> dp(n, std::vector<int>(n, INF));
    for(int l = n - 1; 0 <= l; --l){
        for(int r = 0; r < n; ++r){
            if(r == l){
                // set the dp value at self multiplication zero
                dp.at(l).at(r) = 0;
            }else if(r == l + 1){
                // multiply 2 matrixes
                dp.at(l).at(r) = row.at(l) * col.at(l) * col.at(r);
            }else if(r > l + 1){
                for(int m = l; m < r; ++m){
                    // examine the all dp values in every case where a separating point differs each other
                    dp.at(l).at(r) = std::min(dp.at(l).at(r), dp.at(l).at(m) + row.at(l) * col.at(m) * col.at(r)+ dp.at(m + 1).at(r));
                }
            }
        }
    }

    std::cout << dp.at(0).at(n - 1) << std::endl;

    return 0;
}

C++: #include<bits/stdc++.h>
#define INF 1e9

using namespace std;

int main()
{
  int n;
  int a[105];
  
  cin >> n;

  for(int i=0;i < n;i++){
    cin >> a[i] >> a[i+1];
  }
  //dp[i][j] := iからj番目の行列積に必要なスカラー積の最小値
  int dp[105][105] = {};

  //init
  for(int i=0;i < n;i++){
    for(int j=0;j < n;j++){
      if(i == j) dp[i][j] = 0;//iからiまでは当然 0回
      else dp[i][j] = INF;
    }
  }
  
  for(int m = 0; m < n ;m++){
    for(int i = 0; i+m < n ;i++){
      int j = i+m;
      for(int k = i; k < j ;k++){
	dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + a[i]*a[k+1]*a[j+1]);
      }
    }
  }
  cout << dp[0][n-1] << endl;
  return 0;
}

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

static const int INF = 1000000000;

int main() {
    int n;
    cin >> n;
    vector<int> p(n + 1);
    vector< vector<int> > dp(n + 1, vector<int>(n + 1));
    for (int i = 1; i <= n; i++)
        cin >> p[i - 1] >> p[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] + p[i - 1] * p[k] * p[j]);
            }
        }
    }

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

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

using namespace std;

static const int N = 100;
static const int INF = (1 << 21);

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

    cin >> n;

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

    for (int i = 0; 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; 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 int long long
const int INF = 1e9;

signed main(){
  int N; cin >> N;
  vector<vector<int> > dp(N + 1, vector<int> (N + 1, 0));
  vector<int> r(N + 1);
  for(int i = 1; i <= N; i++) cin >> r[i - 1] >> r[i];
  for(int l = 1; l < N; l++){
    for(int i = 1; i <= N - l; i++){
      int j = l + i;
      dp[i][j] = INF;
      for(int k = i; k < j; k++){
        dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + r[i - 1] * r[k] * r[j]);
      }
    }
  }
  cout << dp[1][N] << endl;
}

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

const int MAX = 1 << 30;

struct Matrix {
  Matrix(int r,int c){
    row = r;
    col = c;
  }
  int row,col;
};

int dp[100][100];

int rec(int left, int right, vector<Matrix>& M)
{
  if(left==right){ return 0; }
  
  if(dp[left][right]<MAX){ return dp[left][right]; }
  
  if(right-left==1){
    dp[left][right] = M[left].row * M[left].col * M[right].col;
    return dp[left][right];
  }
  
  int answer = MAX;
  for(int mid=left;mid<right;mid++){
    //////////////
    //int a = rec(left,mid,M)+rec(mid+1,right,M) + M[mid].row * M[mid].col * M[mid+1].col;
    //cout << "left:" << left << ",mid:" << mid << ",right:" << right << ",answer:" << a << endl;
    //////////////
    answer = min(answer,rec(left,mid,M)+rec(mid+1,right,M) + M[left].row * M[mid].col * M[right].col);
  }
  
  dp[left][right] = answer;
  return dp[left][right];
}


int main(void){
    // Your code here!
    int n;
    cin >> n;
    
    if(n==1){
      cout << 0 << endl;
      return 0;
    }
    
    vector<Matrix> M;
    for(int i=0;i<n;i++){
      int row,col;
      cin >> row >> col;
      M.push_back(Matrix(row,col));
    }
    
    for(int i=0;i<n;i++){
      for(int j=0;j<n;j++){
        dp[i][j] = MAX;
      }
    }
    
    rec(0,n-1,M);

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