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>

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORE(i, a, b) for (int i = (a); i <= (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define REPE(i, n) for (int i = 0; i <= (n); ++i)
#define debug(x) cerr << x << " " \
                      << "(L:" << __LINE__ << ")" << '\n'

typedef long long ll; //64bit型
using namespace std;

const long long INF = 1LL << 60; //無限大の値
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 int             long long
#define REP( i, n )     for( int (i) = 0; (i) < (n); (i)++ )
#define ALL( a )        (a).begin(), (a).end()
#define MP              make_pair

using namespace std;
using P = pair<int, int>;

template<class T>bool chmax( T& a, const T& b ) { if( a < b ) { a = b; return 1; } return 0; }
template<class T>bool chmin( T& a, const T& b ) { if( a > b ) { a = b; return 1; } return 0; }

const int INF = 1e18;
const int MOD = 1e9 + 7;

int dp[101][101];

signed main(){
    int N; cin >> N;
    vector<int> p( N + 1 );
    REP( i, N ){
        cin >> p[i] >> p[i + 1];
    }

    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[j] * p[k] );
            }
        }
    }

    cout << dp[1][N] << endl;
}

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

void fnInput(vector<int>& rvnMtrx)
{
  int nMaxSiz;
  cin >> nMaxSiz;
  rvnMtrx.resize(nMaxSiz + 1);

  for (int i = 0; i < nMaxSiz; ++i)
    cin >> rvnMtrx[i] >> rvnMtrx[i + 1];
}

int fnMtrxChainMultpl(vector<vector<int>>& rvvnDetDP, const vector<int>& cnrvnMtrx)
{
  const int nMAXSIZ = cnrvnMtrx.size() - 1;
  for (int i = 1; i <= nMAXSIZ; ++i)  rvvnDetDP[i][i] = 0;

  for (int nDif = 1; nDif <= nMAXSIZ - 1; ++nDif)
    for (int nRow = 1; nRow <= nMAXSIZ - nDif; ++nRow)
    {
      int nCol = nRow + nDif;
      for (int nx = nRow; nx <= nCol - 1; ++nx)
        rvvnDetDP[nRow][nCol] =
          min(rvvnDetDP[nRow][nCol],
              rvvnDetDP[nRow][nx] + rvvnDetDP[nx + 1][nCol] 
                                  + cnrvnMtrx[nRow - 1] * cnrvnMtrx[nx] * cnrvnMtrx[nCol]);
    }
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  vector<vector<int>> vvnDetDP; 
  vector<int> vnMtrx;

  fnInput(vnMtrx);
  vvnDetDP.resize(vnMtrx.size(), vector<int>(vnMtrx.size(), INT_MAX));

  fnMtrxChainMultpl(vvnDetDP, vnMtrx);
  cout << vvnDetDP[1][vnMtrx.size() - 1] << endl;
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>

using namespace std;

int main() {
	int n;
	cin >> n;
	vector<int> R, C;
	int r, c;
	R.push_back(0);
	for (int i = 0; i < n; ++i) {
		cin >> r >> c;
		R.push_back(r);
	}
	R.push_back(c);

	int cost[100+1][100+1];
	for (int i = 1; i <= n; ++i)
		for (int j = 1; j <= n; ++j)
			cost[i][j] = INT_MAX;
	for (int i = 1; i <= n; ++i)
		cost[i][i] = 0;

	for (int j = 1; j <= n - 1; ++j) {
		for (int i = 1; i <= n - j; ++i) {
			for (int k = i + 1; k <= i + j; ++k) {
				cost[i][i+j] = min(cost[i][i+j], cost[i][k-1] + cost[k][i+j] + R[i]*R[k]*R[i+j+1]);
			}
		}
	}

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

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, to) for (int i = 0; i < (to); i++)
#define rrep(i, to) for (int i = (to) - 1; i >= 0; i--)
#define repf(i, from, to) for (int i = (from); i < (to); i++)
#define all(v) v.begin(), v.end()
#define unless(cond) if (!(cond))
using namespace std;
using ll = long long;
template <typename T>
using V = vector<T>;
template <typename T, typename U>
using P = pair<T, U>;

int inf = INT32_MAX;

int main() {
  int n;
  cin >> n;
  V<int> column;

  rep(i, n) {
    int r, c;
    cin >> r >> c;
    if(i == 0) {
      column.push_back(r);
    }
    column.push_back(c);
  }

  V<V<int>> dp(n + 1, V<int>(n + 1));
  rep(i, n + 1) {
    dp[i][i] = 0;
  }

  int len = 2;
  while(len <= n) {
    for(int i = 1; i + len - 1 <= n; i++) {
      int j = i + len - 1;

      int min_cost = inf;
      for(int k = i; k < j; k++) {
        int cost = dp[i][k] + dp[k + 1][j] + column[i - 1] * column[k] * column[j];
        min_cost = min(min_cost, cost);
      }

      dp[i][j] = min_cost;
    }
    len++;
  }

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