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<iostream>
#include<vector>
#include<algorithm>
#define INF (1<<21)
using namespace std;

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

  vector<int> p(105);
  int m[105][105];

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

  for(int i = 2; i <= n; i++){
    for(int j = 1; j <= n-i+1; j++){
      int x = i + j - 1;
      m[j][x] = INF;

      for(int k = j; k <= x-1; k++){
	m[j][x] = min(m[j][x], m[j][k]+m[k+1][x] + p[j-1]*p[k]*p[x]);
      }
    }
  }

  cout << m[1][n] << endl;

  return 0;

}

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


int main() {
	int n, p[101], m[101][101];
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> p[i - 1] >> p[i];
	
	int i, j, k, l;
	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);
			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]);
			}
		}
	}
	 
	cout << m[1][n] << endl;

	
}

C++: #include <iostream>
#include <vector>
using namespace std;
const int INF = 1001001001;

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

    vector<vector<int>> memo(n, vector<int>(n, INF));
    for(int i = 0; i < n; i++) memo[i][i] = 0;

    for(int i = n-1; i >= 0; i--){
        for(int j = i; j < n; j++){
            for(int k = i; k+1 < n; k++){
                if(memo[i][j] > memo[i][k] + memo[k+1][j] + rnum[i]*rnum[k+1]*rnum[j+1]){
                    memo[i][j] = memo[i][k] + memo[k+1][j] + rnum[i]*rnum[k+1]*rnum[j+1];
                }
            }
        }
    }

    cout << memo[0][n-1] << endl;
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
long long dp[1005][1005];
long long a[1005];
long long b[1005];
int main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//	freopen("a.txt","r",stdin);
	int n;cin>>n;
	for(int i=1;i<=n;i++)
		cin>>a[i]>>b[i];
	memset(dp,0xc,sizeof(dp));
	for(int i=1;i<=n;i++)dp[i][i]=0;
	for(int l=1;l<n;l++){
		for(int i=1;i<=n;i++){
			int j=i+l;
			if(j>n)continue;
			for(int k=i;k<j;k++)
				dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+a[i]*a[k+1]*b[j]);
		}
	}		
	cout<<dp[1][n]<<endl;
	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 <limits>
using namespace std;

int M[101][101] = {};
int p[101];

int matrixChain(int n)
{
    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] = std::numeric_limits<int>::max();

            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 M[1][n];
}

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

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

    cout << matrixChain(n) << endl;

    return 0;
}

C++: #include<iostream>
#include<cassert>
using namespace std;
struct mat
{
	int w;
	int h;
};
typedef struct mat mat_t;
int mulnum(mat_t,mat_t);
long long min(long long a,long long b);

int n;
mat_t a[101];
long long dp[101][101] ;

int main(){
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> a[i].h >> a[i].w;
	}
	for(int x = 0;x<n;x++){
		for(int y =0;y<n;y++){
			dp[x][y] = 2000000;
			if(x == y) dp[x][y] = 0;
		}
	}
	int i = 0;
	int j = 1;
	for(int l = 1;l<n;l++){
		i = 0;
		for(j=l;j<n;j++){
			for(int k = i;i <= k && k < j;k++){
				dp[i][j] = min(dp[i][j],dp[i][k] + dp[k+1][j] + a[i].h *a[k].w * a[j].w);
			}
			i++;
		}
	}
	/*
	for(int x = 0;x<n;x++){
		for(int y=0;y<n;y++){
			cerr << dp[x][y] << " ";
		}
		cerr << endl;
	}
	*/
	cout << dp[0][n-1] << endl;
}

int mulnum(mat_t a,mat_t b){
	assert(a.h == b.w);
	return a.h*a.w*b.h;
}

long long min(long long a,long long b) {
	return a<b? a:b;
}