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 <vector>
using namespace std;

struct TMatrixInfo
{
	int RowSize;
	int ColSize;
	TMatrixInfo(int ARowSize, int AColSize)
	{
		RowSize = ARowSize;
		ColSize = AColSize;
	}
	TMatrixInfo()
	{
	}
};

vector<vector<int> > TableResize(int n)
{
	vector<vector<int> > CostCountTable;
	CostCountTable.resize(n);
	for(int i = 0; i < n; i++){
		CostCountTable[i].resize(n);
	}
	return CostCountTable;
}

int Cost(TMatrixInfo A, TMatrixInfo B)
{
	return A.RowSize * A.ColSize * B.ColSize;
}

TMatrixInfo M(int Index1, int Index2, const vector<TMatrixInfo>& MatrixChain)
{
	TMatrixInfo Matrix(MatrixChain[Index1].RowSize, MatrixChain[Index2].ColSize);
	return Matrix;
}

int GetCellValue(const vector<vector<int> >& CostCountTable, const vector<TMatrixInfo>& MatrixChain, int Row, int Col)
{
	if(Col == Row){
		return 0;
	}else{
		int CurrentMinCost;
		for(int i = Row; i < Col; i++){
			int CurrentCost = CostCountTable[Row][i] + Cost(M(Row, i, MatrixChain), M(i+1, Col, MatrixChain)) + CostCountTable[i+1][Col];
			if(i == Row || CurrentCost < CurrentMinCost){
				CurrentMinCost = CurrentCost;
			}
		}
		return CurrentMinCost;
	}
}

void CalcSlantingLine(vector<vector<int> >& CostCountTable, const vector<TMatrixInfo>& MatrixChain, int Col)
{
	int n = MatrixChain.size();
	for(int i = 0; i < n-Col; i++){
		CostCountTable[i][Col+i] = GetCellValue(CostCountTable, MatrixChain, i, Col+i);
	}
}

int MinCalcCost(const vector<TMatrixInfo>& MatrixChain)
{
	int n = MatrixChain.size();
	vector<vector<int> > CostCountTable = TableResize(n);
	for(int i = 0; i < n; i++){
		CalcSlantingLine(CostCountTable, MatrixChain, i);
	}
	return CostCountTable[0][n-1];
}

int main()
{
	int n;
	cin >> n;
	vector<TMatrixInfo> MatrixChain(n);
	for(int i = 0; i < n; i++){
		cin >> MatrixChain[i].RowSize;
		cin >> MatrixChain[i].ColSize;
	}
	cout << MinCalcCost(MatrixChain) << endl;
	return 0;
}

C++: #define _USE_MATH_DEFIMES
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <climits>
#include <clocale>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <regex>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

const int MOD = 1'000'000'007;
const int INF = 1'000'000'000; //1e9
const int NIL = -1;
const long long LINF = 1'000'000'000'000'000'000; // 1e18
const long double EPS = 1E-10;

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








int main(){
    int n; std::cin >> n;
    std::vector<int> r(n), c(n);
    for(int i(0); i < n; ++i) std::cin >> r[i] >> c[i];
    //dp[i][j] := iからjまでの計算に必要な回数
    std::vector<std::vector<int>> dp(n, std::vector<int>(n, 0));
    for(int d(1); d < n; ++d){
        for(int i(0), i_len(n - d); i < i_len; ++i){
            int j(i + d);
            dp[i][j] = INF;
            for(int k(i); k < j; ++k){
                chmin(dp[i][j], dp[i][k] + dp[k+1][j] + r[i]*c[k]*c[j]);
            }
        }
    }
    std::cout << dp[0][n-1] << std::endl;
    return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<climits>
#include<iostream>
#include<sstream>
#include<utility>
#include<map>
#include<vector>
#include<queue>
#include<algorithm>
#include<set>
#include<stack>
using namespace std;
typedef long long ll;
typedef pair<int,int>P;
int N;
int r[105],c[105];
ll dp[105][105]={0};

void dbg()
{
	for(int i=0;i<N;i++,puts(""))
		for(int j=0;j<N;j++)
			printf("%7d ",dp[i][j]);
}

int main()
{
	scanf("%d",&N);
	for(int i=0;i<N;i++)
		scanf("%d%d",&r[i],&c[i]);
	for(int i=0;i<N;i++)dp[i][i]=0;
	for(int l=1;l<N;l++)
		for(int i=0;i<N-l;i++)
		{
			int j=i+l;
			dp[i][j]=10000000;
			for(int k=0;k<j;k++)
				dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+r[i]*c[k]*c[j]);
		}
	dbg();
	printf("%d\n",dp[0][N-1]);
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define N 100
#define INF 1<<25
int n,p[N+1],m[N+1][N+1];
int matrixchainmultiplication(){
  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]=INF;
      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]);
      }
    }
  }
  return m[1][n];
}
int main(){
  cin>>n;
  for(int i=0;i<n;i++) cin>>p[i]>>p[i+1];
  cout<<matrixchainmultiplication()<<endl;
  return 0;
}
/*
verified on 2017/04/26
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_B
*/