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 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[0].r, matrices[len(matrices)-1].c}, v
	}
	if len(matrices) == 0 {
		panic("must not be empty")
	} else if len(matrices) == 1 {
		return matrices[0], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < len(matrices)-1; i++ {
		formerMatrices := matrices[:i+1]
		latterMatrices := matrices[i+1:]
		matF, countF := calcMinMatrixChainMultiplication(formerMatrices, Range{0, i}, memo)
		matL, countL := calcMinMatrixChainMultiplication(latterMatrices, Range{i + 1, len(matrices) - 1}, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[0].r, matrices[len(matrices)-1].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>
using namespace std;

void dp_solve(vector<vector<long long>> &dp, int l, int r, vector<pair<int, int>> &vp)
{
    if (dp[l][r] != -1)
    {
        return;
    }
    if (l == r)
    {
        dp[l][r] = 0;
        return;
    }
    for (int i = 0; i < r - l; i++)
    {
        dp_solve(dp, l, l + i, vp);
        dp_solve(dp, l + i + 1, r, vp);
    }
    dp[l][r] = 10000000000;
    for (int i = 0; i < r - l; i++)
    {
        dp[l][r] = min(dp[l][r], dp[l][l + i] + dp[l + i + 1][r] + vp[l].first * vp[l + i].second * vp[r].second);
    }
}

int main()
{
    int n;
    cin >> n;
    vector<vector<long long>> dp(n + 1, vector<long long>(n + 1, -1));
    vector<pair<int, int>> vp(n + 1);
    for (int i = 1; i <= n; i++)
    {
        int r, c;
        cin >> r >> c;
        vp[i] = make_pair(r, c);
    }
    dp_solve(dp, 1, n, vp);
    cout << dp[1][n] << endl;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <set>
#include <algorithm>
#include <array>
#include <complex>
#include <utility>
#include <map>
int needleX[4] = { -1,0,1,0 };
int needleY[4] = { 0,1,0,-1 };

int main(void) {
    int n;

    std::cin >> n;
    std::vector<int> p(100+1);
    for (int i = 1; i <= n; i++) {
        std::cin >> p[i-1] >> p[i];
    }
    int m[100 + 1][100 + 1];
    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] = std::min(m[i][j],  m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = i+1; j <= n; j++) {
            std::cout << m[i][j] << " ";
        }
        std::cout << std::endl;
    }
    std::cout << m[1][n] << std::endl;
    return 0;
}

C++: //By Vlgd
#include<bits/stdc++.h>
#define INF 200000000
using namespace std;
int p[101],n;
int dp[101][101];
void solve(){
	for (int i=1;i<=n;i++) dp[i][i]=0;
	for (int i=2;i<=n;i++){
		for (int j=1;j<=n-i+1;j++){
			int b=j+i-1;
			dp[j][b]=INF;
			for (int k=j;k<b;k++)
				dp[j][b]=min(dp[j][b],dp[j][k]+dp[k+1][b]+p[j-1]*p[k]*p[b]);
		}
	} 
	printf("%d\n",dp[1][n]);
}
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		int xx,yy;
		scanf("%d%d",&xx,&yy);
		if (i==1) p[i-1]=xx;
		p[i]=yy;
	}
	solve();
	return 0;
}

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

void compute(vector<vector<int> > & cost,vector<vector<int> > & best,
			 vector<int> & A,int s,int e){
	int minc = 0;
	int mink = -1;
	for(int k=s+1;k<=e;++k){
		if (cost[s][k-1] < 0){
			compute(cost,best,A,s,k-1);
		}
		if (cost[k][e] < 0) {
			compute(cost,best,A,k,e);
		}
		int c = cost[s][k-1] + A[s]*A[k]*A[e+1] + cost[k][e];
		if (mink < 0 || c < minc) {
			minc = c;
			mink = k;
		}
	}
	cost[s][e] = minc;
	best[s][e] = mink;
}

int main(){
	vector<vector<int> > cost,best;
	vector<int> A;
	int n;
	cin >> n;
	A.resize(n+1);
	for(int i=0;i<n;++i) {
		int r,c;
		cin >> r >> c;
		if (i==0){
			A[0] = r;
		}
		if (A[i] != r){ cout << "error";return (0);}
		A[i+1] = c;
	}
	cost.resize(n);
	best.resize(n);
	for(int i=0;i<n;++i){
		cost[i].resize(n);
		best[i].resize(n);
		for(unsigned j=0;j<cost[i].size();++j){
			cost[i][j] = -1;
			best[i][j] = -1;
		}
		cost[i][i]=0;
		best[i][i]=i;
	}
	compute(cost,best,A,0,n-1);
	cout << cost[0][n-1] << std::endl;
	return 0;
}

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

static const int N = 200;

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 <bits/stdc++.h>
using ll = long long;
using namespace std;
#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for(int i = int(a); i < int(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
const long long INFLL = 1LL << 60;
const int INFINT = 1 << 30;
const long long MOD = 1e9 + 7;

int dp[101][101] = {0};
int pa[100];
int solve(int i, int j) {
    if(i == j)
        return dp[i][j] = 0;
    else if(dp[i][j] != 0)
        return dp[i][j];
    else {
        int mi = INFINT;
        int lr = pa[i - 1] * pa[j];
        for(int k = 0; k < j - i; k++) {
            mi =
                min(mi, solve(i, i + k) + solve(i + k + 1, j) + lr * pa[i + k]);
        }
        return dp[i][j] = mi;
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, g;
    cin >> n >> pa[0] >> pa[1];
    rep(i, 1, n) cin >> g >> pa[i + 1];

    rep(i, 1, n + 1) rep(j, 1, n + 1) dp[i][j] = 0;
    rep(i, 1, n) dp[i][i + 1] = pa[i - 1] * pa[i] * pa[i + 1];

    cout << solve(1, n) << endl;
}

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<<10);
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>
using namespace std;

int main()
{
	int n;
	cin >> n;
	for(int i = 0; i < n; i++){
		int a, b;
		cin >> a >> b;
	}
	cout << 0 << endl;
	return 0;
}