Go: package main

/*
連鎖行列積
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

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

type mem *[][]int

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	p := make([]int, n+1)
	for i := 0; i < n; i++ {
		rowcol := eGetInts(scanner)
		p[i] = rowcol[0]
		p[i+1] = rowcol[1]
	}
	m := make([][]int, n)
	for i := 0; i < n; i++ {
		m[i] = make([]int, n)
	}
	// 初期値の格納
	for i := 0; i < n; i++ {
		for j := i; j < n; j++ {
			if i == j {
				m[i][j] = 0 //  同じ行列へのコストは当然0
			} else {
				m[i][j] = math.MaxInt64
			}
		}
	}

	// num : 行列の数. num == 1の場合は初期値0を格納ずみ
	for num := 2; num <= n; num++ {
		// s : スタート行列番号
		for s := 0; s+num <= n; s++ {
			// t : 終了行列番号
			t := s + num - 1
			// k : 仕切
			for k := s; k < t; k++ {
				m[s][t] = min(m[s][t], m[s][k]+m[k+1][t]+p[s]*p[k+1]*p[t+1])
			}
		}
	}
	fmt.Println(m[0][n-1])
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}

// func min(a []int) int {
// 	m := a[0]
// 	for _, v := range a {
// 		if v < m {
// 			m = v
// 		}
// 	}
// 	return m
// }

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

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

static const in N = 100;

int main(){
  int j,i,l,n,p[N+1],m[N+1][N+1];
  scanf("%d",&n);

  for(i = 0;i<=n;i++){
    scanf("%d %d",&p[i-1],&p[i]);
  }

  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);
      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;
using ll = long long;
constexpr ll MOD = 1000000007;
constexpr ll INF = 1ll<<60;

template<class T>
bool chmin(T &a, T b)
{
	if (a > b)
	{
		a = b;
		return false;
	}
	return true;
}

template<class T>
bool chmax(T &a, T b)
{
	if (a < b)
	{
		a = b;
		return false;
	}
	return true;
}

template<class T>
bool chmax(T &a, initializer_list<T> l)
{
	return chmax(a, *max_element(l.begin(), l.end()));
}

template<class T>
bool chmin(T &a, initializer_list<T> l)
{
	return chmin(a, *min_element(l.begin(), l.end));
}

ll dp[110][110];
ll N;
ll P[110];
ll c{0};

ll solve(ll l, ll r)
{
	if (dp[l][r] != -1) return dp[l][r];
	
	//	if (c++ == 10) exit(-1);
	if (abs(l - r) <= 1) return dp[l][r] = 0;

	ll res{INF};
	for (ll mid = l+1; mid < r; ++mid)
	{
		chmin(res, solve(l, mid) + solve(mid, r) + P[l] * P[r] * P[mid]);
	}

	return dp[l][r] = res;
}

int main(int argc, char **argv)
{
	cin >> N;
	for (ll i = 0;i < N; ++i)
		cin >> P[i] >> P[i+1];

	for (ll i = 0; i < 110; ++i) for (ll j = 0; j < 110; ++j) dp[i][j] = -1;
	std::cout << solve(0, N) << std::endl;
}

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 i = 1; i <= n; i++) {
    cin >> p[i-1] >> p[i];
  }

  // 同じindex、つまり行列1個の場合はコスト0
  for (int i = 1; i <= n; i++) m[i][i] = 0;
  // 計算する行列積の長さでループ
  for (int l = 2; l <= n; l++) {
    // 計算し始める行列の始点をずらす
    for (int i = 1; i <= n -l + 1; i++ ) {
      int j = i + l - 1;
      // 1 の 21bit左シフト。要するにinfty
      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>
using namespace std;

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;

   return0;
}

C++: #include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <complex>
#include <ctime>
#include <cstdlib>

using namespace std;

inline int to_int(string s) {int v; istringstream sin(s); sin >> v; return v;}
template<class T> inline string to_str(T x) {ostringstream sout; sout << x; return sout.str();}

typedef long long ll;
typedef pair<int, int> P;
const int INF = 1<<22;

// dp[i][j] := [i , j]??????????????????????????則???????????????????属???即????????属
// |(4*5   (5*3)  3*2)|  2*1
int main()
{
	int n, dp[128][128], r[128];
	P T[128];

	cin >> n;

	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
		 	dp[i][j] = INF;
		}
	}
	/*
	for(int i = 0; i < n; i++)
	{
		dp[i][i] = 0;
	}
	*/
	for(int i = 0; i < n; i++)
	{
		cin >> T[i].first >> T[i].second;
		dp[0][i] = 0;
	}
	/*
	r[0] = T[0].first;
	for(int i = 0; i < n; i++)
	{
		r[i+1] = T[i].second;
	}
	*/
	/*
	for(int i = 0; i <= n; i++)
	{
		cout << r[i] << endl
	}
	*/
	/*
	for(int l = 1; l < n; l++)
	{
		for(int i = 0; i < n-l; i++)
		{ 
			int j = i + l;
			for(int k = 1; k <= l; k++)
			{
				dp[i][j] = std::min(dp[i][j], dp[i][i + k - 1] + dp[i + k][j] + T[i].first*T[i + k].first*T[j].second); //r[j]*r[k]*r[i+j+1]);
			}
		}
	}
*/
	for(int i = 1; i < n; i++)
	{
		for(int j = 0; j < n-i; j++)
		{ 
			for(int k = 1; k <= i; k++)
			{
				dp[i][j] = std::min(dp[i][j], dp[k-1][j] + dp[i-k][j+k] + T[j].first*T[j + k].first*T[j + i].second); //r[j]*r[k]*r[i+j+1]);
				//printf("%3d : %3d : %3d => %3d\n", i, j, k, dp[i][j]);
				//puts("run");
			}
		}
	}

	/*
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			printf("%10d ",dp[i][j]);
		}
		puts("");
	}
    */	

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