Go: package main

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

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func (r Range) length() int {
	return r.end - r.start + 1
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[r.start].r, matrices[r.end].c}, v
	}
	if r.length() == 0 {
		panic("must not be empty")
	} else if r.length() == 1 {
		return matrices[r.start], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < r.length()-1; i++ {
		formerRange := Range{r.start, r.start + i}
		latterRange := Range{r.start + i + 1, r.end}
		matF, countF := calcMinMatrixChainMultiplication(matrices, formerRange, memo)
		matL, countL := calcMinMatrixChainMultiplication(matrices, latterRange, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[r.start].r, matrices[r.end].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <queue>
#include <set>
#include <map>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const int INF = 1e9;

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

    int p[n+1];  // M_iはp[i]行p[i+1]列
    rep(i, n-1) {
        int ri, ci;
        cin >> ri >> ci;
        p[i] = ri; 
    }
    int rn, cn;
    cin >> rn >> cn;
    p[n-1] = rn, p[n] = cn;

    int dp[n][n];  // dp[i][j] : M_i・M_(i+1)・・・M_jの計算回数の最小値(i, jは0-index)
    rep(i, n) {
        rep(j, n) {
            if(i == j) {
                dp[i][j] = 0;
            }
            else {
                dp[i][j] = INF;
            }
        }
    }

    rep(j, n) {
        for(int i = n-1; i >= 0; i--) {
            if(j < i) {
                continue;
            }
            for(int k = i; k < j; k++) {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i]*p[k+1]*p[j+1]);
            }
        }
    }

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

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

static const int N = 100;

int main(){
  int i, j, k, l, n, p[N + 1], m[N + 1][N + 1];
  cin >> n;

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

  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[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
      }
    }
  }

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

  return 0;
}

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

#define NIL -1
#define INF 1000000001

using namespace std;

void minChainMultiple(vector<vector<int> > &minMultipleArray,const vector<int> &matSizeArray){
    int n = (int) minMultipleArray.size();
    for(int l = 1;l < n;l++){
        for(int i = 0;i < n-l;i++){
            int j = i+l;
            minMultipleArray[i][j] = INF;
            for(int k = i;k < j;k++){
                minMultipleArray[i][j] = min(minMultipleArray[i][j],
                minMultipleArray[i][k] + minMultipleArray[k+1][j]+matSizeArray[i]*matSizeArray[k+1]*matSizeArray[j+1]);
            } 
        }
    }
    
}

int main(){
    int n;
    int row,column;
    scanf("%d",&n);
    vector<int> matSizeArray(n+1,0);
    vector<vector<int> > minMultipleArray(n,vector<int>(n,0)); 

    for(int i = 0; i < n;i++){
        scanf("%d %d",&row,&column);
        matSizeArray[i] = row;
        matSizeArray[i+1] = column;
    }
    minChainMultiple(minMultipleArray,matSizeArray);
    printf("%d\n",minMultipleArray[0][n-1]);
    return 0;
}

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

using namespace std;

const int maxn=1e2+5;

int p[maxn],dp[maxn][maxn],n;

int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        cin>>p[i-1]>>p[i];
    }
    for(int i=1;i<=n;i++){
        dp[i][i]=0;
    }
    for(int l=2;l<=n;l++){
        for(int i=1;i<=n-l+1;i++){
            int j=i+l-1;
            dp[i][j]=(1<<21);
            for(int k=i;k<=j-1;k++){
                dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+p[i-1]*p[k]*p[j]);
            }
        }
    }
    cout<<dp[1][n]<<endl;
    return 0;
}
/*
6
30 35
35 15
15 5
5 10
10 20
20 25
*/

C++: #include <bits/stdc++.h>
#pragma GCC optimize ("Ofast", "unroll-loops")
using namespace std;
#define ll long long
#define int ll
#define FOR(i,a,b) for (int i = (a); i<(b); i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n+1)
#define RREP(i,n) for (int i=(n)-1; i>=0; i--)
#define f first
#define s second
#define pb push_back
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)(x.size())
#define SQ(x) (x)*(x)
#define pii pair<int, int>
#define endl '\n'
//#define TOAD
#ifdef TOAD
#define bug(x) cerr<<__LINE__<<": "<<#x<<" is "<<x<<endl
#define IOS()
#else
#define bug(...)
#define IOS() ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#endif
const ll inf = 1ll<<60;
const int iinf=2147483647;
const ll mod = 998244353;
const ll maxn=1e3+5;
ll pw(ll x, ll p){
    ll ret=1;
    while (p>0){
        if (p&1){
            ret*=x;
            ret%=mod;
        }
        x*=x;
        x%=mod;
        p>>=1;
    }
    return ret;
}
ll inv(ll x){
    return pw(x, mod-2);
}
int cosst(pii x, pii y, pii z){
    return x.f*y.s*z.s;
}
signed main(){
    IOS();
    int n; cin>>n;
    vector<pii> vc(n);
    REP(i,n) cin>>vc[i].f>>vc[i].s;
    vector<int> dp[n+2];
    REP(i,n+2){
        dp[i].resize(n+2);
    }
    //cout<<endl;
    for (int i=n;i>=1;i--){
        FOR(j,i+1,n+1){
            dp[i][j]=inf;
            FOR(k,i,j){
                dp[i][j]=min(dp[i][j], dp[i][k]+dp[k+1][j]+cosst(vc[i-1], vc[k-1], vc[j-1]));
            }
            //cout<<i<<' '<<j<<endl;
            //cout<<dp[i][j]<<endl;
        }
    }
    /*REP1(i,n){
        REP1(j,n){
            cout<<i<<' '<<j<<endl;
            cout<<dp[i][j]<<endl;
        }
    }
    */
    cout<<dp[1][n]<<endl;

}

C++: #include<bits/stdc++.h>
#include<limits.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)

static const int N = 100;

int main(){
    int n;
    vector<int> p(N+1);
    vector<vector<int>> m(N+1, vector<int>(N+1, 0));
    cin >> n;

    for(int i = 1; i <= n; i++){
        cin >> p.at(i - 1) >> p.at(i);
    }
    for(int l = 2; l <= n; l++){
        for(int i = 1; i <= n - l + 1; i++){
            int j = i + l - 1;
            m.at(i).at(j) = (1 << 21);
            for(int k = i; k <= j - 1; k++){
                m.at(i).at(j) = min(m.at(i).at(j), m.at(i).at(k) + m.at(k + 1).at(j) + p.at(i - 1) * p.at(k) * p.at(j));
            }
        }
    }
    cout << m.at(1).at(n) << endl;


}

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

static const int N = 105;

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;

}