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 (r Range) length() int {
	return r.end - r.start + 1
}

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[r.start].r, matrices[r.end].c}, v
	}
	if r.length() == 0 {
		panic("must not be empty")
	} else if r.length() == 1 {
		return matrices[r.start], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < r.length()-1; i++ {
		formerRange := Range{r.start, r.start + i}
		latterRange := Range{r.start + i + 1, r.end}
		matF, countF := calcMinMatrixChainMultiplication(matrices, formerRange, memo)
		matL, countL := calcMinMatrixChainMultiplication(matrices, latterRange, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[r.start].r, matrices[r.end].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<bits/stdc++.h>
#define INF 2000000000
#define int long long int
#define MOD 1000000007
#define pb push_back
#define cin1(n) (cin >> n)
#define cin2(a,b) (cin >> a >> b)
#define cin3(a,b,c) (cin >> a >> b >> c)
#define cout(n) (cout << n << endl)
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define fr first 
#define sc second 
#define EPS (1e-10)

using namespace std;

typedef vector<int> vi;
typedef vector< vector<int> > vvi;
typedef vector<pair<int,int>> vpii;
typedef vector<string> vs;
typedef vector<vector<string>> vss;
typedef pair<int,int> pii;

int dx[] = {1,-1,0,0};
int dy[] = {0,0,1,-1};
int n,m;
int a,b;
int p,q;


void printv(vvi v){
	for(int i = 0; i < v.size(); i++){
		for(int j = 0; j < v.size(); j++){
			cout << v[i][j] << " ";
		}
		cout << endl;
	}
	return ;
}


signed main() {
	
	cin1(n);

	vi p(n+2);
	rep(i,1,n+1) {
		cin2(p[i-1],p[i]);
	}

	
	vvi dp(n,vi(n,0));
	for (int i = 2; i <= n; i++) { //???????????°
		for (int j = 0; j < n - i + 1; j++) { //??´???(??????)
			dp[j][j+i-1] = INF;
			for (int k = j; k < j + i - 1; k++ ) { //?????????
				dp[j][j+i-1] = min(dp[j][j+i-1],dp[j][k] + dp[k+1][j+i-1] + p[j] * p[k+1] * p[j+i]);
			}
		}
	}
	//printv(dp);
	cout(dp[0][n-1]);
		
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>

using namespace std;

static const int N = 1000;

int n, p[N + 1], m[N + 1][N + 1];

int main(){
	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 <algorithm>
using namespace std;
int p[105];
int m[110][110];
int n;

int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> p[i-1];
        cin >> p[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] = (i << 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<cstring>
#include<algorithm>
using namespace std;

int mcm(int p[], int n) {
	int m[n+1][n+1];
	memset(m, 0, sizeof(m));

	for (int s = 0; s < n; s++) {
		for (int i = 1, j = s + 2; j <= n; i++, j++) {
			m[i][j] = 1 << 30;
			for (int k = i; k <= j; 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() {
	int n, d;
	cin >> n;
	int p[n+1];
	for (int i = 0; i < n-1; i++) {
		cin >> p[i] >> d;
	}
	cin >> p[n-1] >> p[n];
	int ans = mcm(p, n);
	cout << ans << endl;
	return 0;
}

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

#define N 100

int M[101][101], p[101], n;

int solve()
{
	int l, i, j, k;
	for (l = 2; l <= n; l++) {
		for (i = 1; i <= n - l + 1; i++) {
			j = i + l - 1;
			M[i][j] = INT32_MAX;
			for (k = i; k < j; 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()
{
	ios::sync_with_stdio(false);
	cin.tie(0);

	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;

	cout << solve() << endl;
	return 0;
}

C++: #include<stdio.h>
#include<iostream>
//#include<queue>
#include<algorithm>
using namespace std;
static const int N = 100;

int main() {
	int i, n, m[N + 1][N + 1], p[N + 1];
	//priority_queue<int> PQ;

	scanf("%d", &n);

	for (i = 1; i <= n; i++)scanf("%d %d", &p[i - 1], &p[i]);

	for (i = 1; i <= n; i++) {
		m[i][i] = 0;
	}

	for (int l = 2; l <= n; l++) {
		for (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]);
			}
		}
	}

	printf("%d\n", m[1][n]);

	return 0;
}

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

vector<vector<int> > cost,best;
vector<int> A;

void compute(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(s,k-1);
		}
		if (cost[k][e] < 0) {
			compute(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(){
	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(0,n-1);
	cout << cost[0][n-1] << std::endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, a) for(int i=0; i<(int)(a); i++)
typedef long long ll;
const ll inf = 1LL<<60;

int main()
{
  int n; cin >> n;
  vector<int> p(n+1, 0);
  rep(i, n) cin >> p[i] >> p[i+1];
  vector<vector<ll>> dp(n+1, vector<ll>(n+1, inf));
  rep(i, n+1) dp[i][i] = 0;
  rep(i, n) dp[i][i+1] = 0;
  for (int len=2; len<=n; len++) {
    for (int left=0; left+len<=n; left++) {
      int right = left+len;
      dp[left][right] = inf;
      for (int i=left+1; i<right; i++) {
        dp[left][right] = min(dp[left][right], dp[left][i] + dp[i][right] + p[left]*p[i]*p[right]);
      }
    }
  }
  cout << dp[0][n] << endl;

  return 0;
}