Go: package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, v
	}
	if len(matrices) == 0 {
		panic("must not be empty")
	} else if len(matrices) == 1 {
		return matrices[0], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < len(matrices)-1; i++ {
		formerMatrices := matrices[:i+1]
		latterMatrices := matrices[i+1:]
		matF, countF := calcMinMatrixChainMultiplication(formerMatrices, Range{0, i}, memo)
		matL, countL := calcMinMatrixChainMultiplication(latterMatrices, Range{i + 1, len(matrices) - 1}, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

void compute(vector<vector<int> > & cost,vector<vector<int> > & best,
			 vector<int> & A,int s,int e){
	int minc = 0;
	int mink = -1;
	for(int k=s+1;k<=e;++k){
		if (cost[s][k-1] < 0){
			compute(cost,best,A,s,k-1);
		}
		if (cost[k][e] < 0) {
			compute(cost,best,A,k,e);
		}
		int c = cost[s][k-1] + A[s]*A[k]*A[e+1] + cost[k][e];
		if (mink < 0 || c < minc) {
			minc = c;
			mink = k;
		}
	}
	cost[s][e] = minc;
	best[s][e] = mink;
}

int main(){
	vector<vector<int> > cost,best;
	vector<int> A;
	int n;
	cin >> n;
	A.resize(n+1);
	for(int i=0;i<n;++i) {
		int r,c;
		cin >> r >> c;
		if (i==0){
			A[0] = r;
		}
		if (A[i] != r){ cout << "error";exit(0);}
		A[i+1] = c;
	}
	cost.resize(n);
	best.resize(n);
	for(int i=0;i<n;++i){
		cost[i].resize(n);
		best[i].resize(n);
		for(unsigned j=0;j<cost[i].size();++j){
			cost[i][j] = -1;
			best[i][j] = -1;
		}
		cost[i][i]=0;
		best[i][i]=i;
	}
	compute(cost,best,A,0,n-1);
	cout << cost[0][n-1] << std::endl;
	return 0;
}

C++: // http://algorithms.blog55.fc2.com/blog-entry-66.html

#include <iostream>
using namespace std;
#include <stdio.h>

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

int SIZE;
int R[MAX + 2];
int C[MAX+1][MAX+1]; // cost table
int B[MAX+1][MAX+1]; // best table

void compute(){
    for ( int i = 0; i <= SIZE; i++ )
    for ( int j = 0; j <= SIZE; j++ ) C[i][j] = INFTY;
    
    for ( int i = 0; 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; k < i + j; k++ ){
                // C[i][i+j] = min( C[i][i+j], 
                //                  C[i][k-1] + C[k][i+j] + R[i]*R[k]*R[i+j+1]);
                int cost = C[i][k] + C[k+1][i+j] + R[i]*R[k+1]*R[i+j+1];
                if ( cost < C[i][i+j] ){
                    C[i][i+j] =  cost;
                    B[i][i+j] = k;
                }
                
            }
        }
    }
}

void order( int i, int j ){
    if ( i == j ) cout << "M" << i;
    else{
        cout << "(";
        order( i, B[i][j]-1 ); order(B[i][j], j);
        cout << ")";
    }
}

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

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

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

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<limits>
#define repi(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,a) repi(i,0,a)
#define clr(a,v) memset((a),(v),sizeof(a))

const int MAX_N = 100, INF = std::numeric_limits<int>::max()>>2;

int n;
int r[MAX_N], c[MAX_N];
std::vector<std::vector<int> > dp( MAX_N, std::vector<int>( MAX_N, INF ) );

/*int rec( int b, int e )
{
    if( b == e )
        return dp[b][e] = 0;

    if( ~dp[b][e] )
        return dp[b][e];

    int ret = INF;

    rep( i, e-b )
        ret = std::min( ret, rec( b, b+i )+rec( b+i+1, e )+r[b]*c[b+i]*c[e] );

    return dp[b][e] = ret;
}*/

int main()
{
    scanf( "%d", &n );
    rep( i, n )
        scanf( "%d%d", r+i, c+i );

    rep( i, n )
        dp[i][i] = 0;

    repi( w, 1, n+1 ) rep( i, n ) repi( j, i, i+w )
        dp[i][i+w] = std::min( dp[i][i+w], dp[i][j]+dp[j+1][i+w]+r[i]*c[j]*c[i+w] );

    printf( "%d\n", dp[0][n-1] );

    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[i][n] << endl;
	
	return 0;
}

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

int main() {
    int n;
    cin >> n;

    int R[101];
    int C[101];
    int A[101][101];
    for (int i = 1; i <= n; i++) {
        cin >> R[i] >> C[i];
        A[i][i] = 0;
    }

    for (int k = 2; k <= n; k++) {
        for (int i = 1; i <= (n - k + 1); i++) {
            int j = i + k - 1;
            A[i][j] = 10000001;
            for (int l = i; l < j; l++) {
                A[i][j] = min(A[i][j], A[i][l] + A[l+1][j] + (R[i] * C[l] * C[j]));
            }
        }
    }

    cout << A[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];
  int i,j,k,l;
  cin >>n;
  for(i=1;i<=n;i++){
  cin >>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(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>
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, a, b) for (int i = a; i < b; ++i)
#define FORR(i, a, b) for (int i = b - 1; i >= a; --i)
#define SORT(v) sort(v.begin(), v.end())
#define SORTR(v) sort(v.rbegin(), v.rend())
#define REV(v) reverse(v.begin(), v.end())
#define ITER(itr, v) for (auto itr = v.begin(); itr != v.end(); ++itr)
#define LB(v, x) (lower_bound(v.begin(), v.end(), x) - v.begin())
#define UB(v, x) (upper_bound(v.begin(), v.end(), x) - v.begin())
#define SZ(v) (int)v.size()
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;
	vector<int> c(n + 1);
	REP(i, n) {
		int r;
		cin >> r >> c[i + 1];
		if (i == 0) {
			c[0] = r;
		}
	}
	static int dp[101][101];
	FOR(i, 2, n + 1) {
		REP(j, n - i + 1) {
			int res = INT_MAX;
			FOR(k, 1, i) {
				int l = i - k;
				res = min(res, dp[k][j] + dp[l][j + k] + c[j] * c[j + k] * c[j + i]);
			}
			dp[i][j] = res;
		}
	}
	cout << dp[n][0] << endl;

	return 0;
}