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 <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <unordered_map>
#include <vector>
#include <string.h>
#include <set>

using namespace std;

#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl

template<class T> void printvec(const vector<T>& v) {
  for (auto x : v) { cout << x << " "; }
  cout << endl;
}
template<class T> void printtree(const vector< vector<T> >& tree) {
  for (long long i = 0; i < tree.size(); ++i) {
    cout << i + 1 << ": "; printvec(tree[i]);
  }
}
template<class T, class U> void printmap(const map<T, U>& mp) {
  for (auto x : mp) { cout << x.first << "=>" << x.second << endl; }
}

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

#define rep(i, n) for(ll i = 0; i < n; ++i)
#define all(s) s.begin(), s.end()
#define sz(x) (ll)(x).size()
#define fr first
#define sc second
#define mp make_pair
#define pb push_back
#define eb emplace_back

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> triple;
typedef double D;
typedef vector<ll> vl;
typedef vector<P> vp;

const ll INF = 1e9;
const ll MOD = 1000000007;  // 1e9 + 7

int main(int argc, char** argv) {
  cin.tie(NULL);
  cout.tie(NULL);
  ios_base::sync_with_stdio(false);
  //cout << setprecision(10) << fixed;

  ll n;
  cin >> n;
  vector<ll> r(n);
  vector<ll> c(n);
  rep(i, n) {
    cin >> r[i] >> c[i];
  }

  // dp[i][j] .. min of dp[i][k] + dp[k+1][j] + r[i]*c[k]*c[j]. (dp[i][j] = 0 if i == j).
  vector<vector<ll>> dp(n, vector<ll>(n, INF));
  rep(i,n) { dp[i][i] = 0; }
  rep(d,n+1) {
    rep(i,n) {
      ll j = i+d-1;
      if (j >= n) { continue; }
      for (ll k = i; k < j; ++k) {
        chmin(dp[i][j], dp[i][k] + dp[k+1][j] + r[i]*c[k]*c[j]);
      }
    }
  }
  // printtree(dp);
  cout << dp[0][n-1] << endl;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
#include <cstdlib>
#define INT_MAX 2147483647
#define INT_MIN -2147483646
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
using namespace std;
typedef long long int ll;

ll memo[105][105];
int r[105], c[105];

ll func(int a, int b) {
	if (b - a == 0) { 
		memo[a][b] = 0;
	}
	else {
		ll m = INT_MAX;
		for (int k = a;k < b;k++) {
			m = min(m, func(a, k) + func(k + 1, b) + r[a] * c[k] * c[b]);
		}
		memo[a][b] = m;
	}
	return memo[a][b];
}

int main() {
	int n;
	cin >> n;
	Loop(i, n) {
		cin >> r[i] >> c[i];
	}
	cout << func(0, n - 1) << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define inf 1e9+7

int n;
ll dp[102][102];
ll p[102];

void init(){
    for(int i=0;i<=n;i++){
        for(int j=0;j<=n;j++){
            dp[i][j]=inf;
        }
        dp[i][i]=0;
    }
}

void cal(int l, int r){
    if(l>=r)return;
    if(dp[l][r]<inf)return;
    for(int k=l;k<r;k++){
        cal(l,k);
        cal(k+1,r);
        dp[l][r] = min(dp[l][r], dp[l][k]+dp[k+1][r]+p[l]*p[k+1]*p[r+1]);
    }
}

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

    cin >> n;
    init();
    cin >> p[0] >> p[1];
    ll a,b;
    for(int i=1;i<n;i++){
        cin >> a >> b;
        p[i+1]=b;
    }
    cal(0,n-1);
    cout << dp[0][n-1] << endl;
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cstring>

#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
const int INF=1e9;
int n;
int r[102],c[102];
int p[102];

int dp[102][102];
// [i,j)
int dfs(int i,int j) {
    //cout<<i<<", "<<j<<endl;
    if(dp[i][j]!=-1) return dp[i][j];
    if(j-i==1) return r[i]*c[i]*c[j-1];
    if(i==j) return 0;
    int ret=INF;
    for(int k=i+1;k<j;k++) {
        //ret=min(ret,dfs(i,k)+dfs(k,j)+r[i]*c[k]*c[j-1]);
        ret=min(ret,dfs(i,k)+dfs(k,j)+p[i]*p[k]*p[j]);
    }

    return dp[i][j]=ret;
}

int main() {
    memset(dp,-1,sizeof(dp));
    cin>>n;
    //rep(i,n) cin>>r[i]>>c[i];
    rep(i,n+1) if(i) cin>>p[i-1]>>p[i];
    cout<<dfs(0,n)<<endl;
    return 0;
}