Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	fmt.Println(resolve(parseProblem()))
}

type matrixSize struct{ row, col int }

func calcNum(i, j matrixSize) int {
	return i.row * j.col * i.col
}

func parseProblem() (int, []matrixSize) {
	n := scanInt(sc)
	sizes := make([]matrixSize, n)
	for i := 0; i < n; i++ {
		sizes[i] = matrixSize{row: scanInt(sc), col: scanInt(sc)}
	}
	return n, sizes
}

var dp [][]int

func initDP(n int) {
	dp = make([][]int, n+1)
	for i := 0; i < len(dp); i++ {
		dp[i] = make([]int, n+1)
		for j := 0; j < len(dp[i]); j++ {
			dp[i][j] = math.MaxInt64
		}
	}
}

func resolve(n int, sizes []matrixSize) int {
	// TODO 復習
	initDP(n)
	_rec(sizes, 0, n)
	return dp[0][n]
}

func _rec(sizes []matrixSize, l, r int) int {
	if dp[l][r] != math.MaxInt64 {
		return dp[l][r]
	}
	if r-l <= 1 {
		dp[l][r] = 0
		return 0
	}
	num := math.MaxInt64
	for i := l + 1; i < r; i++ {
		v := _rec(sizes, l, i) + _rec(sizes, i, r) + calcNum(matrixSize{sizes[l].row, sizes[i].row}, matrixSize{sizes[i].row, sizes[r-1].col})
		if v < num {
			num = v
		}
	}
	dp[l][r] = num
	return dp[l][r]
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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;
}

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

struct matrix_size{
	int row;
	int col;
};

int matrixchaincost(vector <matrix_size> &M){
	int n=M.size();
	vector < vector <int> > cost(n, vector <int> (n));
	vector < vector <matrix_size> > X(n, vector <matrix_size> (n));
	for (int i=0; i<n; i++){
		cost[i][i] = 0;
		X[i][i] = M[i];
	}

	for (int length=2; length<=n; length++){
		for (int i=0; i+length<=n; i++){
			int j = i+length-1;
			X[i][j].row = X[i][i].row;
			X[i][j].col = X[j][j].col;
			if (X[i][j-1].col != X[j][j].row){
				cout<<"error"<<endl;
				return NULL;
			}
			int k = i+1;
			int mincost = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
			k++;
			while (k<=j){
				int tmp = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
				if (tmp<mincost)
					mincost = tmp;
				k++;
			};
			cost[i][j] = mincost;
		}
	}
	return cost[0][n-1];
}

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

	vector <matrix_size> M(n);

	for (int i=0; i<n; i++){
		cin>>M[i].row;
		cin>>M[i].col;
	}
	cout<<matrixchaincost(M)<<endl;
	return 0;
}

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

static const int N=100;

using namespace std;

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;
}