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 <bits/stdc++.h>
using namespace std;

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

	vector<int> size(n+1);
	int r,c;
	for (int i=0;i<n;++i)
	{
		cin >> r >> c;
		size[i]=r;
	}
	size[n]=c;

	vector<vector<int>> m(n+1,vector<int>(n+1));
	const int infinity=32768*32767;

	// length=2
	for (int i=0;i<=n-(2-1);++i)
	{
		m[i][i+1]=0;
	}

	// length=3
	for (int i=0;i<=n-(3-1);++i)
	{
		m[i][i+2]=size[i]*size[i+1]*size[i+2];
	}

	// length>=4
	for (int i=4;i<=n+1;++i)
	{
		for (int j=0;j<=n-(i-1);++j)
		{
			int minimum=infinity;
			for (int k=1;k<=i-2;++k)
			{
				int sum=m[j][j+k]+m[j+k][j+i-1]+size[j]*size[j+k]*size[j+i-1];
				minimum=min(minimum,sum);
			}
			m[j][j+i-1]=minimum;
		}
	}

	cout << m[0][n] << endl;
}

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 <climits>
using namespace std;

long int M[101][101];
long int a[1000];
int n;
void solve(){
  for(int i=0;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]=INT_MAX;
       	  for(int k=i;k<j;k++){
	        long int tmp = M[i][k]+M[k+1][j]+a[i-1]*a[k]*a[j];
		M[i][j] = min(M[i][j],tmp);	
	    }
	}
    }
}

int main(){ 
   cin>>n;
   int p, q;
   for(int i=0; i<n; i++){
    cin>>p>>q;
    if(i == 0){
      a[i] = p;
      a[i+1] = q;
    }else{
      a[i+1] = q;
    }
  }

//   for(int i=0;i<2*n;i++)
//	cout<<a[i]<<endl;
   solve();
// for(int i=0;i<=n;i++){
//	for(int j=0;j<=n;j++){
//	    cout<<"("<<i<<","<<j<<")"<<M[i][j]<<" ";
//	}
//	cout<<endl;
 //  }
   cout<<M[1][n]<<endl;
   return 0;
}

C++: #include <bits/stdc++.h>

#define M_PI       3.14159265358979323846   // pi

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ll> VI;
typedef pair<ll, ll> P;
typedef tuple<ll, ll, ll> t3;
typedef tuple<ll, ll, ll, ll> t4;
typedef tuple<ll, ll, ll, ll, ll> t5;

#define rep(a,n) for(ll a = 0;a < n;a++)
#define repi(a,b,n) for(ll a = b;a < n;a++)

using namespace std;

static const ll INF = 1e15;


int main() {
    int n;
    cin >> n;
    vector<P> ps(n);
    rep(i, n) {
        //y,x
        cin >> ps[i].first >> ps[i].second;
    }
    vector<vector<ll>> dp(n, vector<ll>(n, INF));
    rep(i, n) {
        dp[i][i] = 0;
    }
    for (int len = 1; len < n; len++) {
        for (int left = 0; left < n-len; left++) {
            int right = left + len;
            for (int middle = left; middle < right; middle++) {
                ll add1 = ps[left].first * ps[middle].second * ps[right].second;
                ll u1 = dp[left][middle] + dp[middle+1][right] + add1;
                dp[left][right] = min(dp[left][right], u1);
            }
        }
    }
    cout << dp[0][n - 1] << endl;
    return 0;
}

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

/*
 * http://ttrsq.exblog.jp/24318687/
 */

const int MAX_N = 100;
int DP[MAX_N + 1][MAX_N + 1] = {0};
int *p;

int best(int r, int c) {
  int min = INT_MAX;
  int num = c - r;

  for (int i = 0; i < num; i++) {
    min = std::min(min, DP[r][r + i] + DP[r + i + 1][c] + p[r - 1] * p[r + i] * p[c]);
  }
  
  return min;
}

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

  int n = 0;
  std::cin >> n;

  if (n == 1) {
    std::cout << "0" << std::endl;
  }
  
  p = (int *) std::malloc(sizeof(int) * n + 1);

  int bb = 0;

  std::cin >> p[0];
  std::cin >> p[1];
  
  for (int i = 2; i <= n; i++) {
    std::cin >> bb;
    std::cin >> p[i];
  }

  for (int i = 1; i < n; i++) {
    DP[i][i + 1] = p[i - 1] * p[i] * p[i + 1];
  }

  for (int j = 0; j <= n - 3; j++) {
    for (int i = j + 3; i <= n; i++) {
      DP[i - 2 - j][i] = best(i - 2 - j, i);
    }
  }

  std::cout << DP[1][n] << std::endl;

  return 0;
}

C++: #include <bits/stdc++.h>
#define r(i,n) for(int i=0;i<n;i++)
using namespace std;
int dp[111][111],n,L[111],R[111];

int dfs(int l,int r){
	if(dp[l][r]!=-1)return dp[l][r];
	int res=1e9;
	for(int i=l;i<r;i++){
		res=min(res,dfs(l,i)+dfs(i+1,r)+L[l]*R[i]*R[r]);
	}
	return dp[l][r]=res;
}

signed main(){
	memset(dp,-1,sizeof(dp));
	r(i,111)dp[i][i]=0;
	cin>>n;
	r(i,n)cin>>L[i]>>R[i];
	cout<<dfs(0,n-1)<<endl;
}