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 <stdio.h>
#include <stdint.h>
#include <iostream>
#include <fstream>
#include <cassert>
#include <climits>
using namespace std;

#define DEBUG (0)

#if DEBUG
#define DPRINTF(...) do { \
    printf("D(L%d) %s: ", __LINE__, __func__); \
    printf(__VA_ARGS__); \
  } while (false)
#else
#define DPRINTF(...)
#endif // DEBUG


struct Matrix {
  int numOfRow;
  int numOfColumn;
};


struct MinMatrix {
  int minMultiply;
  int numOfRow;
  int numOfColumn;
};


const int kMaxSize = 100;
const int kInvalid = -1;
MinMatrix minArrays[kMaxSize][kMaxSize];


bool isValid(MinMatrix mtx)
{
  return mtx.minMultiply != kInvalid ? true : false;
}

MinMatrix getMinScalarMultiply(const Matrix matrices[], int start, int end)
{
  DPRINTF("start %d  end %d\n", start, end);

  assert(start <= end);

  if (isValid(minArrays[start][end]))
    return minArrays[start][end];

  if (start + 1 == end)
  {
    MinMatrix mtx;

    mtx.minMultiply = 0;
    mtx.numOfRow = matrices[start].numOfRow;
    mtx.numOfColumn = matrices[start].numOfColumn;

    minArrays[start][end] = mtx;

    return minArrays[start][end];
  }


  MinMatrix minMtx;
  minMtx.minMultiply = INT_MAX;

  for (int i = start + 1; i < end; i++)
  {
    MinMatrix mtx0 = getMinScalarMultiply(matrices, start, i);
    MinMatrix mtx1 = getMinScalarMultiply(matrices, i, end);

    MinMatrix mtx;

    mtx.minMultiply = mtx0.minMultiply + mtx1.minMultiply + mtx0.numOfRow * mtx0.numOfColumn * mtx1.numOfColumn;
    mtx.numOfRow = mtx0.numOfRow;
    mtx.numOfColumn = mtx1.numOfColumn;

#if DEBUG
    DPRINTF("start %d  end %d  i %d : mtx.minMultiply %d  min.minMultiply %d\n",
        start, end, i, mtx.minMultiply, minMtx.minMultiply);
    DPRINTF("  mtx0.minMultiply %d  mtx1.minMultiply %d\n",
        mtx0.minMultiply, mtx1.minMultiply);
#endif

    if (minMtx.minMultiply > mtx.minMultiply)
      minMtx = mtx;
  }

  DPRINTF("start %d  end %d  multiply %d\n", start, end, minMtx.minMultiply);

  minArrays[start][end] = minMtx;

  return minArrays[start][end];
}


int calcMinScalarMultiply(const Matrix matrices[], int num)
{
  if (num <= 1)
    return 0;

  MinMatrix mtx = getMinScalarMultiply(matrices, 0, num);

  return mtx.minMultiply;
}


int main() {

  // init
  for (int i = 0; i < kMaxSize; i++)
    for (int j = 0; j < kMaxSize; j++)
      minArrays[i][j].minMultiply = kInvalid;

  int numOfMatrix;
  cin >> numOfMatrix; cin.ignore();

  Matrix  matrices[numOfMatrix];
  for (int i = 0; i < numOfMatrix; i++)
  {
    cin >> matrices[i].numOfRow; cin >> matrices[i].numOfColumn; cin.ignore();
  }

#if DEBUG
  for (int i = 0; i < numOfMatrix; i++)
  {
    DPRINTF("Matrix %d: %d %d\n", i, matrices[i].numOfRow, matrices[i].numOfColumn);
  }
#endif

  cout << calcMinScalarMultiply(matrices, numOfMatrix) << endl;

  return 0;
}

C++: #include <iostream>
#include <vector>
#include <utility>


#define inf 1000000007

using namespace std;

int main(){
	int n;
	cin >> n;
	vector<pair<int,int> > m(n);
	for(int i=0;i<n;++i)cin >> m[i].first >> m[i].second;
	vector<vector<int> > dp;
	dp.resize(n);
	for(int i=0;i<n;++i){
		dp[i].resize(n);
		for(int j=0;j<n;++j)dp[i][j] = 0;
	}
	vector<int> p;
	for(int i=0;i<n;++i)p.push_back(m[i].first);
	p.push_back(m[n-1].second);
	for(int i=1;i<n;++i){
		for(int j=0;j+i<n;++j){
			dp[j][i+j] = inf;
			int t = i+j;
			for(int k=j+1;k<=t;++k){
				dp[j][t] = min(dp[j][t],dp[j][k-1]+dp[k][t]+p[j]*p[k]*p[t+1]);
			}
		}
	}
	cout << dp[0][n-1] << endl;
}