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 <climits>

int main() {
	int n;
	std::cin >> n;
	std::vector<int> matSize(n + 1);
	std::cin >> matSize[0] >> matSize[1];
	for (int i = 2; i < n + 1; i++) {
		int dammy;
		std::cin >> dammy >> matSize[i];
	}

	std::vector<std::vector<long>> costMat(n, std::vector<long>(n, 0));
	// 動的計画法により解く
	for (int i = 0; i < n - 1; i++) {
		costMat[i][i + 1] = matSize[i] * matSize[i + 1] * matSize[i + 2];
	}
	for (int i = 2; i < n; i++) {
		for (int j = 0; j < n - i; j++) {
			long min = LONG_MAX;
			for (int k = 0; k < i; k++) {
				long cost = costMat[j][j + k] + costMat[j + k + 1][i + j];
				cost += matSize[j] * matSize[j + k + 1] * matSize[i + j + 1];
				if (cost < min) {
					min = cost;
					costMat[j][i + j] = min;
				}
			}
		}
	}
	std::cout << costMat[0][n - 1] << std::endl;
}

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

int main(){
	int n; cin >> n;
	vector<int> p(n+1);
	vector<vector<int> > dp(n, vector<int>(n,-1));
	cin >> p[0] >> p[1];
	int a;
	for (int i=0;i<n;i++){
		cin >> a >> p[i+2];
	}
	//前処理
	for (int i=0;i<n;i++) dp[i][i] = 0;
	for (int i=1;i<n;i++) dp[i-1][i] = p[i-1] * p[i] * p[i+1];
	
	//DPの遷移
	for (int i=0;i<n;i++){
		for (int j=0;j<n-i;j++){
			int a = j, b = j + i;
			if (dp[a][b] != -1) continue;
			//実際の処理
			dp[a][b] = 1e9;
			for (int k=a;k<b;k++){
				int now = dp[a][k] + p[a]*p[k+1]*p[b+1] + dp[k+1][b];
				if (dp[a][b] > now)
				dp[a][b] = now;
			}
		}
	}
	
	cout << dp[0][n-1] << endl;
	return 0;

}

C++: #include <algorithm>
#include <iostream>
#include <string>
using namespace std;
static const int MAX = 100;
#define INF (1 << 30);

int store[MAX][MAX] = {{}};

struct matrix {
  int row;
  int col;
};

int nMul(matrix x, matrix y) { return x.row * x.col * y.col; }

matrix mult(matrix x, matrix y) {
  matrix mat;
  mat.row = x.row;
  mat.col = y.col;
  return mat;
}

int main() {
  matrix mat[MAX];
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> mat[i].row;
    cin >> mat[i].col;
  }

  int mcm[MAX][MAX] = {0};

  for (int j = 1; j < n; j++) {
    for (int i = j-1; i >= 0; i--) {
      int minimum = INF;
      for (int k = i; k < j; k++) {
        int joint = nMul(mult(mat[i], mat[k]), mult(mat[k+1], mat[j]));
        int tmp = mcm[i][k] + mcm[k+1][j] + joint;
        minimum = min(minimum, tmp);
      }
      mcm[i][j] = minimum;
    }
  }

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

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

#define debug(x) cout <<"DEBUG"<<" "<< #x << ":" << x << '\n'

// n回繰り返し
#define rep(i,n) for(int i = 0; i < ((int)(n)); i++)   // 0-indexed昇順
#define rep1(i,n) for(int i = 1; i <= ((int)(n)); i++) // 1-indexed昇順
#define rrep(i,n) for(int i = ((int)(n)-1); i >= 0; i--)  // 0-indexed降順
#define rrep1(i,n) for(int i = ((int)(n)); i >= 1; i--)   // 1-indexed降順
#define all(x) (x).begin(),(x).end()

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<vi> vii;  // 2次元配列
typedef vector<ll> vll;
typedef vector<double> vd;
typedef pair<int, int> PII;

template<typename T>
using vec = vector<T>;
template<class T>
using maxheap = std::priority_queue<T>;
template<class T>
using minheap = std::priority_queue<T, std::vector<T>, std::greater<T>>;

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

const ld Pi = std::acos(-1.0L);
const ll infll = (1LL<<62)-1;
const int inf = (1<<30)-1;
const int mod = 1000000007;
// const int mod = 998244353;

int n;
vi m;
vii dp;
/*FUNCs=================================================*/


/*MAIN==================================================*/
signed main(){
    int _StartTime_ = clock();
    cin.tie(nullptr);
    ios::sync_with_stdio(false);   //cin cout 高速化
    // cout << fixed << setprecision(15);

    cin >> n;
    m.resize(n+1);
    dp.resize(n+1, vi(n+1));

    rep(i,n) cin >> m[i] >> m[i+1];

    /*対象とする行列の数を l としてインクリメントしていく
     * 　( ↑　このように区間の大きさ順に処理することでfor文で回しても更新順序の整合性が保たれる )
     * 対象とする行列の範囲を i ~ j とし、その区間を i ~ k , k+1 ~ j として dp loop をまわす
     */
    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; ++k) {
                chmin(dp[i][j], dp[i][k] + dp[k+1][j] + m[i-1]*m[k]*m[j]);
            }
        }
    }
//    rep1(i,n)rep1(j,n) cout << dp[i][j] << (j==n ? '\n' : ' ');

    cout << dp[1][n] << '\n';

    // printf("ExcutionTime: %d /ms\n",1000*(int)((clock()-_StartTime_)/CLOCKS_PER_SEC));
}