Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	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
			//kまでで区切る
			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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

C++: #include<bits/stdc++.h>
#define INF 1e9

using namespace std;

int main()
{
  int n;
  int a[105];
  
  cin >> n;

  for(int i=0;i < n;i++){
    cin >> a[i] >> a[i+1];
  }
  //dp[i][j] := iからj番目の行列積に必要なスカラー積の最小値
  int dp[105][105] = {};

  //init
  for(int i=0;i < n;i++){
    for(int j=0;j < n;j++){
      if(i == j) dp[i][j] = 0;//iからiまでは当然 0回
      else dp[i][j] = INF;
    }
  }
  
  for(int m = 0; m < n ;m++){
    for(int i = 0; m+i < n ;i++){
      int j = m+i;
      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]*a[j+1]);
      }
    }
  }
  cout << dp[0][n-1] << endl;
  return 0;
}

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

int main() {
	int n, p[101], m[101][101];
	std::cin >> n;
	for (int i = 1; i <= n; i++) {
		std::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] = 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 "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

using ll = long long;

int main() {
    // dp[i][j] i番目からj番目までの最小値
    int n;
    cin >> n;
    vector<int> r(n), c(n);
    rep(i, n) cin >> r[i] >> c[i];
    vector<vector<int>> dp(n, vector<int>(n, 1e9));
    rep(i, n) dp[i][i] = 0;
    for (int w = 1; w < n; w++) {
        //cout << "w=" << w << " ";
        for (int a = 0; a + w < n; a++) {
            //cout << "a=" << a << " ";
            int d = 1e9;
            for (int b = a; b <= a + w - 1; b++) {
                //cout << "b=" << b << " ";
                d = min(d, dp[a][b] + dp[b + 1][a + w] + r[a] * c[b] * c[a + w]);
            }
            dp[a][a + w] = d;
            //cout << "dp[" << a << "][" << a + w << "]=" << dp[a][a + w] << "\n";
        }
    }
    cout << dp[0][n - 1] << "\n";
}

C++: import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;

public class Main {
	
	public static void main(String[] args) throws IOException {
		new Main().exec();
	}
	
	int[] rc;
	int[][] min;

	public void exec() throws IOException {
		InputUtil in = new InputUtil();
		PrintWriter out = new PrintWriter(System.out);
		int n = in.nextInt();
		rc = in.nextInt(new int[n*2]);
		min = new int[n][n];
		out.println(minCount(0,n-1));
		out.flush();
	}
	
	private int minCount(int from, int to) {
		int ans=Integer.MAX_VALUE;
		if(from==to) 
			ans = 0;
		else if(from+1==to) 
			ans = rc[from*2]*rc[to*2]*rc[to*2+1];
		else {
			for(int mid=from+1; mid<=to; mid++){
				ans = Math.min(ans, minCount(from,mid-1) + minCount(mid,to) + rc[from*2]*rc[mid*2]*rc[to*2+1]);
			}
		}
		return min[from][to] = ans;
	}
}

class InputUtil {
	//Static Fields
	private static final int BUFSIZ = 100000;
	
	//Fields
	protected InputStream in;
	private byte[] buf = null;
	private int ptr = 0;
	private int max = -1;
	private DataInputStream dis = null;
	//Constructors
	public InputUtil() {this(System.in,BUFSIZ);}
	public InputUtil(InputStream in, int bufsiz) {
		initBuf(bufsiz);
		initIn(in);
	}
	
	//Methods
	//Initializer
	protected void initIn(InputStream in) {dis = new DataInputStream(this.in = in);}
	protected void initBuf(int bufsiz) {buf = new byte[bufsiz];}
	
	//buffer operation
	private void next() throws IOException {ptr++; readBuf();}
	private void readBuf() throws IOException {
		if(ptr >= max && dis.available()>0) {
			if(max>0) Arrays.fill(buf,0,max,(byte)0);
			max = dis.read(buf);
			ptr = 0;
		}
	}
	
	//Number Input Reader/Parser
	private boolean isNum(byte b) {return '0' <= b && b <= '9'; }
	private boolean isMinus(byte b) {return b=='-'; }

	private int _nextInt() throws IOException {
		int sign = 1;
		int res = 0;
		byte c;
		while (!isNum(c=buf[ptr]) && !isMinus(c)) 
			next();
		if (isMinus(buf[ptr])) {
			sign = -1;
			next();
		}
		while (isNum(c=buf[ptr])) {
			res *= 10;
			res += c - '0' ;
			next();
		}
		next();
		return sign * res;
	}
	
	public int nextInt() throws IOException {
		readBuf();
		return _nextInt();
	}

	public int[] nextInt(int[] result) throws IOException {
		readBuf();
		for(int i=0; i<result.length; i++) {
			result[i] = _nextInt();
		}
		return result;
	}
	
	//Close 
	public void close() throws IOException {
		if(!this.in.equals(System.in)) 
			this.in.close();
	}

}

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

void MatrixChainMultiplication(int n,int p[],int m[101][101]) {
	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] = 100000000;
			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]);
			}
		}
	}
}

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

	
}

C++: #include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<limits>
#define repi(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,a) repi(i,0,a)
#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];
std::vector<std::vector<int> > dp( MAX_N, std::vector<int>( MAX_N, INF ) );

/*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 );

    rep( i, n )
        dp[i][i] = 0;

    repi( w, 1, n ) rep( i, n ) if( i+w < n ) repi( j, i, i+w )
        dp[i][i+w] = std::min( dp[i][i+w], dp[i][j]+dp[j+1][i+w]+r[i]*c[j]*c[i+w] );

    printf( "%d\n", dp[0][n-1] );

    return 0;
}