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 <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i < (n);i++)
#define ALL(obj) (obj).begin(),(obj).end()
using namespace std;

const long long INF = 1LL << 60;
const int MOD = (int)1e9 + 7;
typedef long long ll;
//約数列挙
vector<long long> divisor(long long n) {
    vector<long long> ret;
    for (long long i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            ret.push_back(i);
            if (i * i != n) ret.push_back(n / i);
        }
    }
    //sort(ret.begin(), ret.end()); // 昇順に並べる
    return ret;
}
vector<int> dx={1,0,-1,0};vector<int> dy={0,-1,0,1};

signed main () {
    int m;scanf("%d",&m);
    vector<vector<int>> cost(m+1,vector<int>(m+1));
    vector<int> p(m+1);
    FOR(i,1,m+1){
        int a,b;scanf("%d %d",&a,&b);
        p[i-1] = a;p[i]=b;
    }
    REP(i,m)cost[i][i] = 0;
    int min_cost;
    for (int l = 2; l <= m; l++) {  // 行列の個数
        for (int i = 1; i <= m - l + 1; i++) {
            int j = i + l - 1;
            for (int k = i; k < j; k++) {
                if (k == i) min_cost = cost[i][k] + cost[k+1][j] + p[i-1] * p[k] * p[j];
                else min_cost = min(min_cost, cost[i][k] + cost[k+1][j] + p[i-1] * p[k] * p[j]);
            }
            cost[i][j] = min_cost;
        }
    }
    cout << cost[1][m] << endl;
}

C++: #include<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<numeric>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define dump(a) (cerr << #a << "=" << (a) << endl)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;

using namespace std;

struct matrix {
	int r, c;
	matrix(int r_ = 0, int c_ = 0) : r(r_), c(c_) {}
};

const int INF = 100000000;
vector<vector<int>> dp;

int mul(int r1, int rm, int c2) { return r1 * c2 * rm; }

int main() {
	int N;
	cin >> N;
	int R, C;
	vector<matrix> mats(N);	
	dp.assign(N+1, vector<int>(N+1, INF)); //[l, r)
	rep(i, N) {
		cin >> R >> C;
		mats[i] = matrix(R, C);
	}

	for(int len = 1; len < N+1; ++len) {
		for(int l = 0; l <= N-len; ++l) {
			int r = l + len;	
			if(l+1 == r) {
				dp[l][r] = 0;	
				continue;	
			}		
			for(int m = l+1; m < r; ++m) {	
				int r1 = mats[l].r;
				int rm = mats[m].r;
				int c2 = mats[r-1].c;
				dp[l][r] = min(dp[l][m] + dp[m][r] + mul(r1, rm, c2), dp[l][r]);
			}
		}
	}
	cout << dp[0][N] << endl;
	return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
static const int N = 101;
int main()
{
    int n;
    int p[N],m[N][N];
    cin>>n;
    for (int i = 1; i <= n; i++)
    {
        cin>>p[i-1]>>p[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<cstdio>
#include<algorithm>
using namespace std;
#define MAX 100
int p[MAX+1] = {0};
int m[MAX+1][MAX+1] = {0};

int main()
{
	int n;
	int a,b;
	scanf("%d" ,&n);
	for(int i=0; i<n; i++)
	{
		scanf("%d%d", &a, &b);
		if(i == 0) p[0] = a;
		p[i+1] = b;
	}

	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 << 30);
			for(int k=i; k<j; k++)
				m[i][j] = min(m[i][j], m[i][k] + m[k+1][j] + p[i-1] * p[k] * p[j]);
		}
	}

	printf("%d\n",m[1][n]);

	return 0;


}

C++: #include <bits/stdc++.h>
#define r(i,n) for(int i=0;i<n;i++)
#define int long long
using namespace std;
int dp[111][111],n,L[111],R[111];

int dfs(int l,int r){
	if(dp[l][r]!=-1)return dp[l][r];
	if(l==r)return 0;
	int res=1e17;
	for(int i=l;i<r;i++){
		res=min(res,dfs(l,i)+dfs(i+1,r)+L[l]*R[i]*R[r]);
	}
	return dp[l][r]=res;
}

signed main(){
	memset(dp,-1,sizeof(dp));
	cin>>n;
	r(i,n)cin>>L[i]>>R[i];
	dfs(0,n-1);
	cout<<dp[0][n-1]<<endl;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
int n;//計算する行列の数
const int MAX_N =110;
int dp[MAX_N][MAX_N];//dp[i][j]:=Ai...Ajの計算に必要な最小のコスト
pii A[MAX_N];//行列firstを行secondを列とする。
void init(){
	for(int i =0; i < n;i++){
		for(int j = 0;j < n;j++){
			dp[i][j]=INF;
		}
	}
	for(int i =0;i < n;i++){
		dp[i][i]=0;
	}
}

int solve(){
	for(int k =1;k <n;k++){
		for(int i =0;i <n-k;i++){
			for(int j =i;j <i+k;j++){
				int sz =A[i].first*A[j].second*A[i+k].second;
				dp[i][i+k]=
				min(dp[i][i+k],dp[i][j]+dp[j+1][i+k]+sz);
			}
		}
	}
	return dp[0][n-1];
}

int main(){
	cin>>n;
	init();
	for(int i =0;i < n;i++){
		cin>>A[i].first>>A[i].second;
	}
	cout <<solve()<<endl;
	return 0;
}