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 <algorithm>
#include <vector>
#include <utility>
#include <queue>
#include <climits>
using namespace std;

int mcm(vector<int>& p)
{
    vector<vector<int> > m(p.size() - 1, vector<int>(p.size() - 1));
    for (int i = 0; i < m.size(); i++) {
        m[i][i] = 0;
    }
/*
 * l == number of targets
 * i == left most of targets
 */
    for (int l = 2; l <= m.size(); l++) {
        for (int i = 0; i < m.size() - l + 1; i++) {
            int j = i + l - 1;
            m[i][j] = INT_MAX;
            for (int k = i; k < j; k++) {
                m[i][j] =
                    min(m[i][j],
                        m[i][k] + m[k + 1][j] + p[i] * p[k + 1] * p[j + 1]);
            }
        }
    }
    return m[0][m.size() - 1];
}

int main()
{
    int n;
    cin >> n;
    vector<int> p(n + 1);
    for (int i = 1; i < n + 1; i++) {
        cin >> p.at(i - 1) >> p.at(i);
    }
    cout << mcm(p) << 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[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]);
}
}
}
cout << m[1][n]<< endl;

return 0;

}

C++: #include <iostream>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <vector>
#include <cstdlib>
#include <list>
#define _USE_MATH_DEFINES
#include <math.h>

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];
	}

	for (int i = 1; i <= n; i++)m[i][i] = 0;

	for (int i = 2; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			int k = i + j - 1;
			m[j][k] = (1 << 21);
			for (int l = j; l <= k - 1; l++) {
				m[j][k] = min(m[j][k], m[j][l] + m[l + 1][k] + p[j - 1] * p[l] * p[k]);
			}
		}
	}

	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
struct MX{
	int r,c;
} mx[105];
long long dp[105][105];
int main()
{
	int n; cin>>n;
	for(int i=1;i<=n;i++){
		cin>>mx[i].r>>mx[i].c;
	}
	for(int i=i;i<=n;i++) dp[i][i] = 0;
	for(int k=1;k<n;k++){
		for(int i=1;i<=n-k;i++){
			int j = i+k;
			long long mini=1e19,t;
			for(int a=i;a<j;a++){
				t = dp[i][a]+dp[a+1][j]+mx[i].r*mx[a].c*mx[j].c;
				mini = min(mini,t);
			}
			dp[i][j] = mini;
		}
	}
	cout<<dp[1][n]<<endl;
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <stack>
#include <map>
#include <queue>
#include <cmath>
#include <iomanip>
#include <set>
#include <functional>

#define MOD (1000000007)

using namespace std;

typedef long long ll;
typedef pair<ll, ll> tup;
const int MAX = 3000000;

long long fac[MAX], finv[MAX], inv[MAX];


ll modpow(ll a, ll n, ll mod) {
    ll res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}


// テーブルを作る前処理
void COMinit() {
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < MAX; i++){
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }
}

// 二項係数計算
long long COM(int n, int k){
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

map<ll,ll> prime;//素因数分解でそれぞれの素数がいくつ出てきたかを保存するmap

//O(√n)
//整列済み(mapはkeyで自動で整列される)
void prime_factorize(ll n){
    if(n<=1) return;
    ll l=sqrt(n);
   for(ll i=2;i<=(ll)(l);i++) { //
        if(n%i==0){
            prime_factorize(i);prime_factorize(ll(n/i));return;
        }
    }
    //mapでは存在しないkeyの場合も自動で構築される
    prime[n]++;return;
} 


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

    vector<pair<ll, ll>> v;

    for(ll i = 0; i < n; i++) {
        ll r, c;
        cin >> r >> c;
        v.push_back(make_pair(r,c));
    }

    vector<vector<ll>> dp(n+1, vector<ll>(n+1, 999999999999999999));
    for(ll i = 0; i < n; i++) {
        dp[i][i+1] = 0;
    }
    for(ll i = 0; i < n-1; i++) {
        dp[i][i+2] = v[i].first * v[i].second * v[i+1].second;
    }

    for(ll diff = 3; diff <= n; diff++) {
        //cout << diff << endl;
        for(ll i = 0; i + diff <= n; i++) {
            //cout << "*** [" << i <<", " << i+diff << ")" << endl;
            for(ll after = i+1; after <= i+diff-1; after++) {
                // cout << "-> [" << i << ", " << after << ") + [" << after << ", " << i+diff << ")" << endl;
                // cout <<  dp[i][after] + dp[after][i+diff] + v[i].first * v[after-1].second * v[i+diff-1].second << endl;
                dp[i][i+diff] = min(dp[i][i+diff], dp[i][after] + dp[after][i+diff] + v[i].first * v[after-1].second * v[i+diff-1].second);
                //cout << "dp[" << i << "][" << i+diff << "] = " << dp[i][i+diff] << endl;
            }
        }
    }

    cout << dp[0][n] << endl;

    return 0;    
}