Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	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] = 1 << 21
			//kまでで区切る
			for 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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

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 < cnrvnMtrx.size(); ++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
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <tuple>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <climits>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s)
{
    int v;
    istringstream sin(s);
    sin >> v;
    return v;
}
template <class T>
inline string toString(T x)
{
    ostringstream sout;
    sout << x;
    return sout.str();
}

//math
//-------------------------------------------
template <class T>
inline T sqr(T x) { return x * x; }

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

//container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i, c) for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())

//repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);

//clear memory
#define CLR(a) memset((a), 0, sizeof(a))

//debug
// #define dump(x) cerr << #x << " = " << (x) << endl;
// #define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" \
//                       << " " << __FILE__ << endl;

class MCM_Solver
{
private:
    vector<tuple<LL, LL>> dims;
    vector<VL> dp;

public:
    LL solve_dp();
    MCM_Solver(vector<tuple<LL, LL>> dims, size_t n) : dims(dims), dp(n, VL(n, LONG_MAX))
    {
        REP(i, n)
        {
            dp[i][i] = 0;
        }
    }
};

LL MCM_Solver::solve_dp()
{
    int n = dp.size();
    FOR(l, 2, n + 1)
    {
        FOR(i, 0, (n - l + 1))
        {
            int j = i + l - 1;
            LL ans = LONG_MAX;
            FOR(k, i, j)
            {
                ans = min(
                    ans,
                    dp[i][k] + dp[k + 1][j] + get<0>(dims[i]) * get<0>(dims[k + 1]) * get<1>(dims[j]));
            }
            dp[i][j] = ans;
            // cout << i << ", " << j << ", " << dp[i][j] << endl;
        }
    }

    return dp[0][n - 1];
}

int main()
{
    // cout << LONG_MAX << endl;

    int n;
    cin >> n;
    vector<tuple<LL, LL>> dims;
    REP(i, n)
    {
        int nn, m;
        cin >> nn >> m;

        dims.push_back(make_tuple(nn, m));
    }

    LL ans = MCM_Solver(dims, n).solve_dp();

    cout << ans << endl;
}

C++: #include <algorithm>
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <string>
#include <sstream>
#include <vector>
#include <set>
#include <stack>
#include <map>
#include <cmath>
#include <queue>
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
using namespace std;
typedef unsigned long ll;
#define MAX_N 101


int dp[MAX_N][MAX_N];
int p[MAX_N];



int main()
{
	int n;
	cin>>n;
	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] = (1<<21);
			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++: #ifdef BUILT_LOCAL

#include "niklib.h"

#endif

#include <iostream>
#include <utility>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <string>
#include <cstdio>
#include <map>
#include <cmath>
#include <set>
#include <list>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef __int128 lll;
constexpr ll mod = 1000000007;

int n, r[100], c[100];
ll dp[101][101];

ll rec(int s, int t) {
    if (s + 1 == t) return 0;
    if (dp[s][t] == 0) {
        dp[s][t] = INT32_MAX;
        for (int i = s + 1; i < t; i++) {
            dp[s][t] = min(dp[s][t], rec(s, i) + rec(i, t) + r[s] * r[i] * c[t - 1]);
        }
    }
    return dp[s][t];
}

int main() {
    cin >> n;
    for (int i = 0; i < n; i++) cin >> r[i] >> c[i];
    cout << rec(0, n) << endl;
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define MAX 100
int min(int,int);
int p[MAX]={},m[MAX][MAX]={};

int min(int n1,int n2){
  if(n1>=n2) return n2;
  else return n1;
}

int main()
{
  int n,r,l,i,j,k;
  
  scanf("%d",&n);
  
  for(i=1;i<=n;i++){
    scanf("%d %d",&p[i-1],&p[i]);
  }
  
  for(l=2;l<=n;l++){
    for(i=1;i<=n-l+1;i++){
      j=i+l-1;
      m[i][j]=(1<<21);
      for(k=i;k<=j-1;k++){
	m[i][j]=min(m[i][j],m[i][k]+m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
      }
    }
  }
  
  printf("%d\n",m[i][n]+1000);
  
  return 0;
}