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>
#include <math.h>
#include <vector>
#include <queue>
#include <iomanip>
#include <string>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep_1 (i,j,n) for(int i=j;i<n;i++)
typedef long long ll;
typedef long l;
const ll l_INF = 1010101010101010;
const int INF = 1010101010;
const int dx[] = {-1,0,1,0,-1,-1,1,1};
const int dy[] = {0,-1,0,1,1,-1,1,-1};
ll dp[110][110];
ll m[2][110];

ll solve(int x,int y){
  if(dp[x][y]!=l_INF) return dp[x][y];
  ll ans=l_INF;
  for(int i=x+1;i<=y;i++){
    ans=min(ans,solve(x,i-1)+solve(i,y)+m[0][x]*m[1][i-1]*m[1][y]);
  }
  //cout<<ans<<endl;
  return dp[x][y]=ans;
}
int main(){
  int n; cin>>n;
  rep(i,n) cin>>m[0][i]>>m[1][i];
  rep(i,n)rep(j,n) dp[i][j]=l_INF;
  rep(i,n) dp[i][i]=0;
  rep(i,n-1) dp[i][i+1]=m[0][i]*m[0][i+1]*m[1][i+1];
  cout<<solve(0,n-1)<<endl;
}

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

using namespace std;

int main(void) {
	int n;
	cin >> n;
	vector< pair<int,int> > mat(n);
	for (int i = 0; i < n; ++i) {
		cin >> mat[i].first >> mat[i].second;
	}
	vector< vector<int> > dp(n,vector<int>(n,(1 << 28)));
	for (int i = 0; i < n; ++i) {
		dp[i][i] = 0;
	}
	for (int k = 1; k < n; ++k) {
		for (int i = 0; i < n-k; ++i) {
			for (int j = 0; j < k; ++j) {
				dp[i][i+k] = min(dp[i][i+j]+dp[i+j+1][i+k]+(mat[i].first*mat[i+j+1].first*mat[i+k].second),dp[i][i+k]);
			}
		}
	}
	cout << dp[0][n-1] << endl;
	return 0;
}

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

using namespace std;

template <class T>
T Vec(T v) { return v; }

template <class T, class... Ts>
auto Vec(size_t l, Ts... ts) {
    return vector<decltype(Vec<T>(ts...))>(l, Vec<T>(ts...));
}

const int INF = 1 << 30;

int N;
vector<int> deg;

int rec(int l, int r) {
    static auto dp = Vec<int>(N + 1, N + 1, -1);
    if (r - l <= 1) return 0;
    if (dp[l][r] >= 0) return dp[l][r];
    dp[l][r] = INF;

    for (int p = l + 1; p < r; ++p) {
        dp[l][r] = min(dp[l][r], rec(l, p) + rec(p, r) + deg[l] * deg[p] * deg[r]);
    }
    return dp[l][r];
}

int main() {
    cin >> N;

    deg.resize(N + 1);
    for (int i = 0; i < N; ++i) {
        int r, c;
        cin >> r >> c;
        deg[i] = r;
        if (i == N - 1) deg[i + 1] = c;
    }
    cout << rec(0, N) << endl;
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define lng long long
#define D(x) cout << #x " is " << x << endl

int n;
int rows[105];
int cols[105];
lng mem[105][105];

lng solve(int s, int e){
	if(s == e) return 0;
	
	lng &ret = mem[s][e];
	if(~ret) return ret;
	
	lng res = LLONG_MAX;
	lng curRes, cost;
	for(int i = s; i<e; i++){
		cost = 1LL*rows[s]*cols[i]*cols[e];
		curRes = cost + solve(s,i) + solve(i+1,e);
		res = min(res, curRes);
	}
	
	return ret = res;
}

int main(){
	// ios_base::sync_with_stdio(false);
	// cin.tie(NULL);
	// cout.tie(NULL);
	
	scanf("%d", &n);
	for(int i = 0; i < n; i++){
		scanf("%d%d", &rows[i], &cols[i]);
	}

	memset(mem, -1, sizeof mem);
	
	lng ans = solve(0, n-1);
	printf("%lld\n", ans);
	
	return 0;
}

C++: #include <stdio.h>
#include <string.h>
#define N 110
#define INF_MAX 0x3f3f3f3f
int p[N];
int m[N][N];
int n;
int main(){
    scanf("%d", &n);
    for(int i = 0; i < n; i++) scanf("%d %d", &p[i], &p[i+1]);
    for(int i = 0; i < n; i++) m[i][i] = 0;
    for(int len = 2; len <= n; len++){
        for(int i = 1; i <= n-len+1; i++){
            int j = i+len-1;
            m[i][j] = INF_MAX;
            for(int k = i; k < j; k++){
                int temp = m[i][k] + m[k+1][j] + p[i-1]*p[k]*p[j];
                m[i][j] = m[i][j] < temp ? m[i][j] :temp;
            }
        }
    }
    printf("%d\n", m[1][n]);
    return 0;
}

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

#define REP(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define INF 999999999

int main() {
  int n; cin >> n;
  int p[n + 1], m[n][n];
  REP(i, n) {
    cin >> p[i] >> p[i + 1];
  }

  REP(i, n) m[i][i] = 0;
  FOR(l, 2, n + 1) {
    REP(i, n - l + 1) {
      int j = i + l - 1;
      m[i][j] = INF;
      FOR(k, i, j) {
        m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + p[i] * p[k + 1] * p[j + 1]);
      }
    }
  }
  cout << m[0][n - 1] << endl;;
  return 0;
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
#include <cstring>
#include <deque>
#include <iomanip>
#include <limits>
#include <fstream>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
ll memo[111][111];
int n, a[111], b[111];
ll rec(int l, int r){
    if(memo[l][r] != 1e9) return memo[l][r];
    if(l == r) return memo[l][r] = 0;
    if(r - l == 1){
      return memo[l][r] = a[l]*b[l]*b[r];
    }
    ll ret = 1e9;
    FOR(m, l, r){
      ret = min(ret, rec(l, m) + rec(m + 1, r) + a[l] * b[m] * b[r]);
    }
    return memo[l][r] = ret;
}
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  FOR(i,0,n) cin >> a[i] >> b[i];
  FOR(i,0,111)FOR(j,0,111)memo[i][j]=1e9;
  cout << rec(0,n-1) << endl;
}