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<cstdio>
#include<cstring>
#include<limits>
#define rep(i,a) for(int i=0;i<(a);++i)
#define clr(a,v) memset((a),(v),sizeof(a))

const int MAX_N = 100, INF = std::numeric_limits<int>::max()>>2;

int n;
int r[MAX_N], c[MAX_N];
int dp[MAX_N][MAX_N];

int rec( int b, int e )
{
    if( b == e )
        return dp[b][e] = 0;

    if( ~dp[b][e] )
        return dp[b][e];

    int ret = INF;

    rep( i, e-b )
        ret = std::min( ret, rec( b, b+i )+rec( b+i+1, e )+r[b]*c[b+i]*c[e] );

    return dp[b][e] = ret;
}

int main()
{
    scanf( "%d", &n );
    rep( i, n )
        scanf( "%d%d", r+i, c+i );

    clr( dp, -1 );

    printf( "%d\n", rec( 0, n-1 ) );

    return 0;
}

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

int r[105];
int c[105];
int cache[105][105];

int f(int a, int b) {
    if (a == b) return 0;
    if (cache[a][b] == -1) {
        cache[a][b] = 2000000000;
        for (int i = a; i < b; i++) {
            int res = f(a, i) + f(i + 1, b) + r[a] * c[i] * c[b];
            if (res < cache[a][b]) cache[a][b] = res;
        }
    }
    return cache[a][b];
}

int main(void) {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> r[i];
        cin >> c[i];
    }
    memset(cache, -1, sizeof(cache));
    cout << f(0, n-1);
}

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

class MatrixChainMultiplication {
private:
	int n, *r, *c;
	int memory[100][100];
public:
	MatrixChainMultiplication(int _n, int _r[], int _c[]) {
		n = _n;
		r = _r;
		c = _c;
		for (int i=0; i<n; i++) {
			for (int j=1; j<=n; j++) {
				memory[i][j] = INT_MAX;
			}
		}
	}
	int count(int start, int end) {
		if (memory[start][end] != INT_MAX)
			return memory[start][end];
		
		if (start + 1 == end) {
			memory[start][end] = 0;
		} else {
			int temp;
			for (int i=start+1; i<end; i++) {
				temp = count(start, i) + count(i, end) + (r[start] * r[i] * c[end - 1]);
				if (memory[start][end] > temp) memory[start][end] = temp;
			}
		}
		return memory[start][end];
	}
};

int main() {
	int n, r[100], c[100];
	
	cin >> n;
	for (int i=0; i<n; i++) {
		cin >> r[i] >> c[i];
	}
	
	auto mcm = MatrixChainMultiplication(n, r, c);
	
	cout << mcm.count(0, n) << '\n';
	
	return 0;
}

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

#define MAX_SIZE (110)
int P[MAX_SIZE];
int M[MAX_SIZE][MAX_SIZE];

int main()
{
  int N;
  std::cin >> N;
  for (int i = 1; i <= N; ++i)
  {
    std::cin >> P[i - 1] >> P[i];
  }

  for (int i = 0; i <= N; ++i) M[i][i] = 0;
  for (int n = 2; n <= N; ++n)
  {
    for (int i = 1; i <= N - n + 1; ++i)
    {
      int j = i + n - 1;
      M[i][j] = 1 << 30;
      for (int k = i; k < j; ++k)
      {
        M[i][j] = std::min(M[i][j], M[i][k] + M[k + 1][j] + P[i - 1] * P[k] * P[j]);
      }
    }
  }

  std::cout << M[1][N] << std::endl;

  return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;
int main(){
	int n;
	int p[101], m[101][101];
	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;
}