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>
#define all(x) (x).begin(), (x).end()
typedef long long ll;
#define MOD 1000000007
using namespace std;
ll n;
vector<ll> r(100), c(100);
vector<vector<ll> > dp(101, vector<ll>(101, -1));
int dfs(int v, int w) {
    // cout << v << ":" << w << endl;
    if(dp[v][w] != -1) {
        return dp[v][w];
    } else {
        ll tmp = INT_MAX / 3;
        for(int i = v + 1; i < w; i++) {
            tmp = min(tmp, dfs(v, i) + dfs(i, w) + r[v] * r[i] * c[w - 1]);
        }
        dp[v][w] = tmp;
        return tmp;
    }
}
int main() {
    cin >> n;
    for(int i = 0; i < n; i++) {
        cin >> r[i] >> c[i];
    }
    for(int i = 0; i < n; i++) {
        dp[i][i] = 0;
        dp[i][i + 1] = 0;
    }
    dfs(0, n);
    cout << dp[0][n] << endl;
}

C++: #include <iostream>

using namespace std;

const int N = 100;

int min(int a, int b){
    return a > b ? b : a;
}

int main()
{
    int n;
    int rc[N+1];
    int mat[N + 1][N] = {};
    cin >> n;

    for (int i = 0; i < n; i++)
    {
        cin >> rc[i] >> rc[i + 1];
    }

    // 行列の長さl
    for (int l = 2; l < n + 1; l++)
    {
        // i番目の積 積の数は : n - l + 1
        for (int i = 1; i < n - l + 2; i++)
        {
            mat[l][i] = (1 << 21);
            for (int k = 1; k < l; k++)
            {
                mat[l][i] = min(mat[l][i], mat[k][i] + mat[l - k][i + k] + rc[i-1] * rc[i+k-1] * rc[i+l-1]);
            }
        }
    }

    cout << mat[n][1] << endl;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

ll dp[100][100];
vector<pair<int,int>> matrix(100);


ll kukandp(int i, int j){
    if(dp[i][j]!=INF)return dp[i][j];
    if(j-i==0)dp[i][j]=0;
    if(j-i==1)dp[i][j]=matrix[i].first*matrix[i].second*matrix[j].second;

    if(j-i>1){
        for(int k=i; k<j; k++){
            dp[i][j]=min(dp[i][j], kukandp(i,k)+kukandp(k+1,j)+matrix[i].first*matrix[k].second*matrix[j].second);
        }
    }

    return dp[i][j];
}

int main(){
    int N; cin>>N;
    rep(i,N){
        cin>>matrix[i].first>>matrix[i].second;
    }
    rep(i,100)rep(j,100)dp[i][j]=INF;
    cout<<kukandp(0,N-1)<<endl;
    return 0;
}

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<string>
#include<vector>
#include<stack>
#include<bitset>
#include<cstdlib>
#include<cmath>
#include<set>
#include<list>
#include<deque>
#include<map>
#include<queue>
#define LL long long
using namespace std;
int main()
{
    int a[200],n,m[200][200],i;
    cin>>n;
    for (i=1; i<=n; i++)
    {
        cin>>a[i-1]>>a[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]+a[i-1]*a[k]*a[j]);
            }
        }
    }
    cout<<m[1][n]<<endl;
    return 0;
}

C++: #define _USE_MATH_DEFINES

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <list>

long long int INF = 1e18;
using namespace std;

typedef pair<long long int, long long int> P;

int main(){
	
	int n;
	cin >> n;
	
	int A[200], B[200];
	
	for(int i = 0; i < n; i++){
		cin >> A[i] >> B[i];
	}
	
	long long int DP[101][101] = {};
	for(int i = 1; i < n; i++){
		for(int j = 0; j + i < n; j++){
			DP[j][j + i] = INF;
			for(int k = 0; k < i; k++){
				DP[j][j + i] = min(DP[j][j + i], DP[j][j + k] + DP[j + k + 1][j + i] + A[j] * B[j + k] * B[j + i]);
				//cout << DP[j][j + k] + DP[j + k + 1][j + i] + A[j + k] * B[j + k] * B[j + k + 1] << " ";
			}
			//cout << DP[j][j + i] << " ";
		}
		//cout << endl;
	}
	
	cout << DP[0][n - 1] << endl;
	
	return 0;
}