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 <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()
#define INF 1<<25

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

int a[105];
int dp[105][105];

int main()
{
	memset (a, 0, sizeof (a ) );
	memset (dp, 0, sizeof (dp ) );

	ios_base::sync_with_stdio(0);
	int n; cin >> n;

	rep (i, n+1 ) for (int j = i+1; j < n+1; j++ ) dp[i][j] = INF;

	
	rep (i, n ){
		int r, c; cin >> r >> c;
		a[i] = r; a[i+1] = c;
	} // end rep

	for (int i = n; i >= 1; i-- ){
		for (int j = i; j <= n; j++ ){
			for (int k = i; k < j; k++ ){
				int curr = dp[i][k] + dp[k+1][j];
				dp[i][j] = min (dp[i][j], curr + a[i-1]*a[k]*a[j] );
			} // end for
		} // end for
	} // end for

	int res = dp[1][n];
	cout << res << endl;

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i=0; i < (n);++i)
using namespace std;
template <class _t> inline bool chmax (_t& a,_t b){if(a<b){a=b;return true;}return false;} template <class _t> inline bool chmin (_t& a,_t b){if(a>b){a=b;return true;}return false;}

const long long inf = 1ll << 60;
const long long mod = 1000000007;

int dx[4] = {1,0,-1,0};int dy[4] = {0,-1,0,1};

int main() {
    int n;cin >> n;
    vector<int> p(n+1,0);
    for(int i=0;i<n;i++){
	cin >> p[i] >> p[i+1];
	//p[0] M1の行 p[1] M１の列
    }
    vector<vector<int> > dp(n+1,vector<int>(n+1,(1<<21)));
    rep(i,n+1) dp[i][i] = 0;
    for(int t = 2;t<=n;t++){
	for(int i=1;i<=n-t+1;i++){
	    int j=i+t-1;
	    for(int k=i;k<=j-1;k++){
		chmin(dp[i][j],dp[i][k]+dp[k+1][j]+p[i-1]*p[k]*p[j]);
	    }
	}
    }
    /*
    for(int i=0;i<=n;i++){
	for(int j=0;j<=n;j++){
	    cout << dp[i][j] << " ";
	}
	cout << endl;
    }
    */
    cout << dp[1][n] << endl;
    return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
#define MAX_N 100
#define INF (1 << 21)
int cost[MAX_N][MAX_N];
int rc[MAX_N+1];

int main() {
  int n; cin >> n;
  for(int i=0;i<n;i++) {
    int tmp;
    if(i==0) {
      cin >> rc[i] >> rc[i+1];
    }
    else {
      cin >> tmp >> rc[i+1];
    }
  }

  // cost[i][i] = 0
  /*
  for(int i=0;i<n;i++) {
    cost[i][i] = 0;
  }
  */
  // cost[i][i+1] = rc[i]*rc[i+1]*rc[i+2]
  for(int i=0;i<n-1;i++) {
    cost[i][i+1] = rc[i]*rc[i+1]*rc[i+2];
  }
  // calculation cost[i][i+j]
  for(int j=2;j<n;j++) {
    for(int i=0;i+j<n;i++) {
      cost[i][i+j] = INF;
      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] + rc[i]*rc[k]*rc[i+j+1]);
      }
    }
  }

  cout << cost[0][n-1] << endl;
}

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

static const int N=100;

//求解矩阵链乘法的最优解
//p 用于存储矩阵的行和列的
//dp[i][j] 表示从矩阵i乘到矩阵j的最小乘法次数

int main(){
    int n;
    int p[N+1],dp[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++){
        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);//取一个很大的值
            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++: #define _USE_MATH_DEFINES
#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <string>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <list>
#include <utility>
#include <numeric>

using namespace std;
typedef long long llong;
typedef unsigned long long ullong;

const ullong MOD = 1000000000 + 7;

const int N = 101;

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

	vector<int> p(N);
	for (int i = 1; i <= n; i++)
	{
		cin >> p.at(i - 1) >> p.at(i);
	}

	vector<vector<int>> m(N, vector<int>(N));

	for (int l = 2; l <= n; l++)
	{
		for (int i = 1; i <= n - l + 1; i++)
		{
			int j = i + l - 1;
			m.at(i).at(j) = (1 << 21);
			for (int k = i; k < j; k++)
			{
				m.at(i).at(j) = min(m.at(i).at(j), m.at(i).at(k) + m.at(k + 1).at(j) + p.at(i - 1) * p.at(k) * p.at(j));
			}
		}
	}

	cout << m.at(1).at(n) << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;

// m[i][j]はM_i...M_jの最小コスト
vector<vector<int> > m(101, vector<int>(101));
// M_iはP[i-1]xP[i]行列
vector<int> P(101);

int n;

void solve()
{
  // M_iの最小コストをメモ
  for (int i = 1; i <= n; i++)
  {
    m.at(i).at(i) = 0;
  }
  for (int l = 2; l <= n; l++)
  {
    // 長さlの行列積の最小コストをメモ
    for (int i = 1; i <= n - l + 1; i++)
    {
      int j = i + l - 1;
      // M_i...M_jの最小コストを、M_i...M_kの最小コストとM_k...M_jの最小コストを参照して計算する
      m.at(i).at(j) = (1 << 21); // 2の21乗
      for (int k = i; k <= j - 1; k++)
      {
        m.at(i).at(j) = min(m.at(i).at(j), m.at(i).at(k) + m.at(k + 1).at(j) + P.at(i - 1) * P.at(k) * P.at(j));
      }
    }
  }
}

int main()
{
  cin >> n;
  for (int i = 0; i < n; i++)
  {
    int r, c;
    if (i == 0)
    {
      cin >> r >> c;
      P.at(0) = r;
      P.at(1) = c;
    }
    else
    {
      cin >> r >> c;
      P.at(i + 1) = c;
    }
  }

  solve();

  cout << m.at(1).at(n) << endl;
}