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<stdio.h>
//#include <bits/stdc++.h>
#include<vector>
#include<float.h>
#include<iomanip>
#include<algorithm>
#include<string>
#include<cstring>
#include<math.h>
#include<cmath>
#include<sstream>
#include<set>
#include<map>
#include<queue>
#include <cassert>
#include <cmath>
#include<cstdint>

#define INF 1e9
#define rep(i,n)for(int i=0;(i)<(int)(n);i++)
#define REP(i,a,b)for(int i=(int)(a);(i)<=(int)(b);i++)
#define VEC(type, c, n) std::vector<type> c(n);for(auto& i:c)std::cin>>i;
#define vec(type,n) vector<type>(n)
#define vvec(m,n) vector<vector<int>> (int(m),vector<int>(n))
#define ALL(a)  (a).begin(),(a).end()
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)


using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;
using P = pair<ll, ll>;

int N;
vector<P> p(105);
ll dp[105][105];
queue<P> que;
ll rec(int l = 0, int r = N){
    if(r - l <= 1)return 0;
    if(r - l == 2){
        return p[l].first * p[l].second * p[r-1].second;
    }
    ll &ret = dp[l][r];
    if(ret != INF)return ret;
    for(int i = l + 1; i <= r - 1; i++){
        ll rr = rec(l, i) + rec(i, r) + (p[l].first * p[i].first * p[r-1].second);
      que.push(P(i, rr));
        chmin(ret, rr);
    }
    return ret;
}

int main(){
    cin >> N;
    rep(i, N){
        ll a, b;
        cin >> a >> b;
        p[i] = P(a, b);
    }
    rep(i, 105)rep(j, 105)dp[i][j] = INF;
    ll res = rec();

  //cout << p[1].first << " " << p[1].second << " " << p[2].second << endl;
    cout << res << endl;
}

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

int N ;
int a[101][101];
int m[101][2];

int main() {
    cin >> N;
    for (int i = 1; i <= N; ++i) {
        cin >> m[i][0] >> m[i][1];
    }

    for (int j = 1; j <= N; ++j) {
        a[j][j] = 0;
    }

    for (int k = 1; k < N; ++k) {
        for (int l = 1; l <= N- k ; ++l) {
            int j = l + k;
            int mn = INT_MAX;
            for (int p = l; p <= j-1 ; ++p) {
                mn = min(mn, a[l][p] + a[p+1][j] + m[l][0] * m[p][1] * m[j][1]);
            }
            a[l][j] = mn;
        }
    }
    cout << a[1][N] << 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[k + 1][j] + p[i - 1]*p[k]*p[j]);
    }
  }
}
   cout << m[1][n] << endl;

   return 0;
}

C++: #include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<vector>
#include<queue>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int,int> PII;
typedef long long LL;

#define d(x)  cout<<#x<<" = "<<(x)<<endl;
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define REACH(i,c) for(typeof((c).rbegin()) i=(c).rbegin(); i!=(c).rend(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c,n) sort(c,c+n)
#define VSORT(c) sort((c).begin(),(c).end())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define DFOR(i,b,a) for(int i=(b)-1;i>=(a);--i)
#define DREP(i,n) DFOR(i,n,0)
#define INF 2000000000

const double EPS = 1e-10;
const double PI  = acos(-1.0);
////////////////////////////////////////////////

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

const int INF = 1000010;

int MCMP(int N, int R[], int C[]) {
    int dp[N][N];
    rep(i, N) rep(j, N) {
        if (i==j) dp[i][j] = 0;
        else dp[i][j] = INF;
    }
    for (int len=0; len<=N; len++) {
        for (int s=0; s+len<N; s++) {
            int left = s, right = s+len;
            for (int mid=left; mid<right; mid++) {
                int lmr_num;
                lmr_num = dp[left][mid] + dp[mid+1][right] + R[left] * C[mid] * C[right];
                dp[left][right] = min(dp[left][right], lmr_num);
                // cout << " " << left << " " << right << " " << mid << " " << dp[left][right] << endl;
            }
        }
    }
    return dp[0][N-1];
}


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

    int R[N], C[N];
    rep(i, N) cin >> R[i] >> C[i];

    cout << MCMP(N, R, C) << endl;

    return 0;
}

C++: #include <iostream>
#include <string>
#include <map>
#include <set>
#include <algorithm>
using namespace std;
#define MAX 100000

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[k+1][j]+p[i-1]*p[k]*p[j]);
      }
    }
  }
  cout << m[1][n] << endl;
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
const int64_t INF = (1 << 21);
const int64_t MAXN = 110;
int64_t DP[MAXN][MAXN];

int main()
{
  int64_t N;
  cin >> N;
  vector<int64_t> M(N + 1);
  for (int i = 1; i <= N; i++)
    cin >> M[i - 1] >> M[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] = INF;
      for (int k = i; k <= j - 1; k++)
      {
        DP[i][j] = min(DP[i][j], DP[i][k] + DP[k + 1][j] + M.at(i - 1) * M.at(k) * M.at(j));
      }
    }
  }
  cout << DP[1][N] << endl;
}