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 <climits>
#include <vector>
using namespace std;

struct matrix {int r, c;};
typedef matrix M;
#define v vector
typedef v<int> vi;
typedef v<vi> vvi;
typedef v<M> vm;

vm m;
vvi t;

int McM(int b, int e) {
	int r = t[b][e];
	if (r != INT_MAX)
		return r;
	if (b == e)
		r = 0;
	else
		for (int i = b; i < e; i++)
			r = min(r, McM(b, i) + McM(i + 1, e) + m[b].r * m[i].c * m[e].c);
	t[b][e] = r;
	return r;
}

int main() {
	int n;
	cin >> n;
	m = vm(n);
	t = vvi(n, vi(n, INT_MAX));
	for (M &x: m)
		cin >> x.r >> x.c;
	cout << McM(0, n - 1) << endl;
}

C++: #include <cstdio>
#include <cstring>
#include <climits>
#include <algorithm>

using namespace std;

int r[100], c[100];
int dp[100][100];

int optMat(int left, int right)
{
	if (dp[left][right] >= 0){
		return (dp[left][right]);
	}
	if (left == right){
		return (0);
	}
	
	int res = INT_MAX;
	for (int i = left; i < right; i++){
		res = min(res, optMat(left, i) + optMat(i + 1, right) + r[left] * c[i] * c[right]);
	}
	
	return (dp[left][right] = res);
}

int main()
{
	int N;
	
	scanf("%d", &N);
	
	for (int i = 0; i < N; i++){
		scanf("%d %d", &r[i], &c[i]);
	}
	
	memset(dp, -1, sizeof(dp));
	
	printf("%d\n", optMat(0, N - 1));
	
	return (0);
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cassert>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define rep(i,n) FOR(i,0,n)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define vint vector<int>
#define vdouble vector<double>
#define vstring vector<string>
using namespace std;

#include<map>
#include<set>
#include<queue>

typedef long long ll;
typedef unsigned long long ull;

const int MAX_N = 1000000;
const int MAX_L = 10000;
int N;

struct Matrix{ int R, W; };
Matrix M[MAX_N];

int mem[MAX_L][MAX_L];
Matrix memM[MAX_L][MAX_L];


void eval(Matrix M[], int s, int e){

	if (s == e){
		mem[s][e] = 0;
		memM[s][e] = M[s];
		return;
	}

	int minval = 1000000000;
	for (int mid = s; mid < e; mid++){
		Matrix m1 = memM[s][mid];
		Matrix m2 = memM[mid+1][e];
		int val = mem[s][mid] + mem[mid+1][e] + (m1.W * m1.R * m2.W);
		
		if (val < minval){
			minval = val;
			mem[s][e] = val;
			Matrix m; m.R = m1.R; m.W = m2.W;
			memM[s][e] = m;
		}
	}

}

int solve(Matrix M[], int N){

	for (int d = 0; d <= N; d++)
		for (int s = 0; s + d <= N; s++)
		{
			eval(M, s, s + d);
		}

	return mem[0][N];
}

int main() {

	cin >> N;
	rep(i, N){
		Matrix m;
		cin >> m.R;
		cin >> m.W;
		M[i] = m;
	}

	cout << solve(M, N) << endl;

	// debug
	rep (i, N){
		rep(j, N){
			cerr << mem[i][j] << ' ';
		}
		cerr << endl;
	}
}

C++: #include<iostream>
#include<stdio.h>
#include<algorithm>

using namespace std;

void output(int, int, int, int);

#define MAX 100
#define INF (1 << 21)

int SIZE;
int R[MAX + 2];
int C[MAX + 1][MAX + 1];
int B[MAX + 1][MAX + 1];

void compute() {
	for (int i = 1; i <= SIZE; i++)
		for (int j = 1; j <= SIZE; j++) C[i][j] = INF;

	for (int i = 1; i <= SIZE; i++) C[i][i] = 0;

	for (int j = 1; j <= SIZE - 1; j++) {
		for (int i = 1; i <= SIZE - j; i++) {
			for (int k = i + 1; k <= i + j; k++) {
				int cost = C[i][k - 1] + C[k][i + j] + R[i] * R[k] * R[i + j + 1];
				if (cost < C[i][i + j]) {
					C[i][i + j] = cost;
					B[i][i + j] = k;
				}

			}
		}
	}
}


void input() {
	int r, c;
	cin >> SIZE;
	for (int i = 1; i <= SIZE; i++) {
		cin >> r;
		cin >> c;
		R[i] =r;
	}
	R[SIZE + 1] = c;

}

void output() {
	cout << C[1][SIZE] << endl;
}

int main() {
	input();
	compute();
	output();
}

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;

  return 0;
}