Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	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
			//kまでで区切る
			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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

C++: #include <iostream>
#include <vector>
#include <numeric>
#include <algorithm>

using vvi = std::vector<std::vector<int>>;

void solve()
{
    using namespace std;

    constexpr int inf = (1 << 23);

    int n;
    cin >> n;

    vector<int> d(n + 1);

    for (int i = 0; i < n; ++i)
    {
        cin >> d[i];
        if(i + 1 != n)
            cin.ignore(numeric_limits<streamsize>::max(), ' ');
    }

    cin.ignore(numeric_limits<streamsize>::max(), ' ');
    cin >> d[n];

    vvi dp (n, vector<int>(n, 0));

    //自分自身との積は乗算が発生しない
    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] = inf;
            for (int k = i; k < j; ++k)
            {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + d[i] * d[k + 1] * d[j + 1]);
            }
        }
    }

    cout << dp[0][n - 1] << endl;
}

int main()
{
    solve();
        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[1][n] << endl;

  return 0;
}

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

vector<pair<int,int> > matrices;
vector<vector<int> > memoization;

int minCost(int i, int j) {
  if (j == i)
    return 0;
  if (memoization[i][j])
    return memoization[i][j];
  int current_min = INT_MAX;
  for (int k = i; k < j; k++) {
    int current_cost =
      matrices[i].first *
      matrices[k].second *
      matrices[j].second +
      minCost(i, k) + minCost(k+1, j);
    if (current_cost < current_min)
      current_min = current_cost;
  }
  memoization[i][j] = current_min;
  return memoization[i][j];
}

int main(int argc, char **argv) {
  ios_base::sync_with_stdio(false);
  int n;
  cin >> n;
  matrices = vector<pair<int,int> > (n, pair<int,int>(0,0));
  memoization = vector<vector<int> > (n, vector<int> (n, 0));
  for (int i = 0; i < n; i++)
    cin >> matrices[i].first >> matrices[i].second;
  cout << minCost(0, n-1) << endl;
  return 0;
}

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

class TMinimumMultiplications
{
	std::vector<std::vector<int> > FTable;
	std::vector<std::pair<int, int> >& FMatrixChain;
	
	int GetMinimum(int Begin, int End);
public:
	TMinimumMultiplications(std::vector<std::pair<int, int> >& MatrixChain);
	
	int Get(int Begin, int End);
};

TMinimumMultiplications::TMinimumMultiplications(std::vector<std::pair<int, int> >& MatrixChain)
: FMatrixChain(MatrixChain), FTable(MatrixChain.size(), std::vector<int>(MatrixChain.size(), -1))
{
}

int TMinimumMultiplications::GetMinimum(int Begin, int End)
{
	int Minimum = INT_MAX;
	for(int i = Begin; i < End; ++i){
		int Total = Get(Begin, i) + Get(i + 1, End) + FMatrixChain[Begin].first * FMatrixChain[i + 1].first * FMatrixChain[End].second;
		if(Minimum > Total) Minimum = Total;
	}
	return Minimum;
}

int TMinimumMultiplications::Get(int Begin, int End)
{
	if(Begin == End) return 0;
	if(FTable[Begin][End] < 0){
		FTable[Begin][End] = GetMinimum(Begin, End);
	}
	return FTable[Begin][End];
}

int main()
{
	int Count;
	std::cin >> Count;
	std::vector<std::pair<int, int> > MatrixChain;
	for(int i = 0; i < Count; ++i){
		int Row, Col;
		std::cin >> Row >> Col;
		MatrixChain.push_back(std::make_pair(Row, Col));
	}
	TMinimumMultiplications Minimum(MatrixChain);
	std::cout << Minimum.Get(0, MatrixChain.size() - 1) << std::endl;
	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 - 1];
}

int main() {

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

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

#ifdef DEBUGRUN
	rep (i, N){
		rep(j, N){
			cerr << mem[i][j] << ' ';
		}
		cerr << endl;
	}
#endif

}

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;
}