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 <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;
}