Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	fmt.Println(resolve(parseProblem()))
}

type matrixSize struct{ row, col int }

func calcNum(i, j matrixSize) int {
	return i.row * j.col * i.col
}

func parseProblem() (int, []matrixSize) {
	n := scanInt(sc)
	sizes := make([]matrixSize, n)
	for i := 0; i < n; i++ {
		sizes[i] = matrixSize{row: scanInt(sc), col: scanInt(sc)}
	}
	return n, sizes
}

var dp [][]int

func initDP(n int) {
	dp = make([][]int, n+1)
	for i := 0; i < len(dp); i++ {
		dp[i] = make([]int, n+1)
		for j := 0; j < len(dp[i]); j++ {
			dp[i][j] = math.MaxInt64
		}
	}
}

func resolve(n int, sizes []matrixSize) int {
	// TODO 復習
	initDP(n)
	_rec(sizes, 0, n)
	return dp[0][n]
}

func _rec(sizes []matrixSize, l, r int) int {
	if dp[l][r] != math.MaxInt64 {
		return dp[l][r]
	}
	if r-l <= 1 {
		dp[l][r] = 0
		return 0
	}
	num := math.MaxInt64
	for i := l + 1; i < r; i++ {
		v := _rec(sizes, l, i) + _rec(sizes, i, r) + calcNum(matrixSize{sizes[l].row, sizes[i].row}, matrixSize{sizes[i].row, sizes[r-1].col})
		if v < num {
			num = v
		}
	}
	dp[l][r] = num
	return dp[l][r]
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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;
}

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 n = 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 (i = 1; i <= n; 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<iostream>
#include<algorithm>
#include<cmath>
#include<vector>
#include<string>
using namespace std;
int main()
{
  int num;
  cin>>num;
  vector<int> m(num+1);
  for(int i=0;i<num;i++) cin>>m.at(i)>>m.at(i+1);

  //dp[i][j]はi行列iからjまでの計算回数の最小値を格納している
  int dp[num+1][num+1];
  //スタートとゴールは等しくならないので0を入れる
  for(int i=1;i<=num;i++) dp[i][i]=0;


  //対象とする行列の数l
  for(int l=2;l<=num;l++)
  {
    for(int i=1;i<=num-l+1;i++)
    {
      int j=i+l-1;
      dp[i][j]=(1<<21);
      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][num]<<endl;


}