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 <vector>
#include <array>

using namespace std;

long minimum_product(const vector<int>& vec, int p, int q, vector<vector<int>>& dp){
    if(q-p <= 1){
        return 0;
    }
    if(dp[p][q]){
        return dp[p][q];
    }
    int ret = 2000000000;
    for(int i = p+1; i < q; ++i){
        int product = vec[p]*vec[q]*vec[i] + minimum_product(vec, p, i, dp)
                    + minimum_product(vec, i, q, dp);
        if(product < ret){
            ret = product;
        }
    }
    return dp[p][q] = ret;
}

int main(){
    vector<int> vec {};
    int n;
    cin >> n;
    for(int i = 0; i < n; ++i){
        int a, b;
        cin >>  a >> b;
        if(i == 0){
            vec.push_back(a);
        }
        vec.push_back(b);
    }
    vector<vector<int>> dp {n+1, vector<int>(n+1, 0)};
    cout << minimum_product(vec, 0, n, dp) << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll=long long;
//const ll MOD=(ll)1e9+7;
const ll MOD=(ll)998244353;
const ll INF=(ll)1e18+10;
const double PI=acos(-1);

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
int dy[]={-1,1,0,0};
int dx[]={0,0,-1,1};

ll dp[110][110];
int row[110],col[110];

ll dfs(int l, int r){
    if(r-l<=1) return 0;
    ll ret=INF;
    for(int i=l+1;i<r;++i){
        if(dp[l][i]==INF) dp[l][i]=dfs(l,i);
        if(dp[i][r]==INF) dp[i][r]=dfs(i,r);
        chmin(ret,dp[l][i]+dp[i][r]+row[l]*col[r-1]*row[i]);
    }
    return dp[l][r]=ret;
}

void solve(int ca){
    int N; cin>>N;
    for (int i = 0; i < N; ++i) {
        cin>>row[i]>>col[i];
    }
    for (int i = 0; i <= N; ++i) {
        for(int j=0;j<=N;++j) dp[i][j]=INF;
    }

    cout<<dfs(0,N)<<endl;

}

//#define MULTI
int main() {
#ifdef MULTI
    int N; cin>>N;
    for (int i = 0; i < N; ++i) {
        solve(i+1);
    }
#else
    solve(1);
#endif
    return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <algorithm>
using namespace std;
const int num = 105;
int p[num];
int main() {
	int n;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		scanf("%d%d", &p[i-1], &p[i]);
	}
	int m[num][num];
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			m[i][j] = 999999999999;
		}
	}
	for (int i = 1; i <= n; i++) m[i][i] = 0;
	for (int l = 1; l < n; l++) {
		for (int i = 1; i < n - l + 1; i++) {
			int j = i + l;
			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]);
		}
	}
	cout << m[1][n] << endl;
	return 0;
}

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

static const int N = 100;
static const long long INFTY = (1 << 21);

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] = INFTY;
            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;
}

C++: #include<cstdio>
#include<cstring>

#define MIN(X,Y) ((X)>(Y)?(Y):(X))

int r[1000], c[1000];
int dp[200][200];

int main(void) {
    int n;
    scanf("%d",&n);

    for(int i=0; i<n; i++)
        scanf("%d%d",&r[i],&c[i]);

    memset(dp, 0x7F, sizeof(dp));

    for(int i=0; i<n; i++)
        dp[i][i] = 0;
    for(int i=0; i<n-1; i++)
        dp[i][i+1] = r[i]*c[i+1]*r[i+1];

    for(int d=2; d<n; d++)
        for(int i=0; i+d<n; i++)
            for(int j=i; j<i+d; j++)
                dp[i][i+d] = MIN(dp[i][i+d], dp[i][j]+r[i]*c[i+d]*r[j+1]+dp[j+1][i+d]);

    printf("%d\n",dp[0][n-1]);
    return 0;
}

C++: #include <cstdio>
int N, MEMO[100][100], V[100][100];
struct info {
    int r;
    int c;
};
struct info MAT[100];
int DP(int i, int j);
void input(void);
int main(void){
    //freopen("in.txt", "r", stdin);
    input();
    printf("%d\n", DP(0, N - 1));
    return 0;
}
int DP(int i, int j){
    if (V[i][j] == 1) return MEMO[i][j];
    V[i][j] = 1;
    if (i >= j) return 0;
    int min = 987654321;
    for(int k = i; k < j; k++){
        int cnd = DP(i, k) + DP(k + 1, j) + MAT[i].r * MAT[k].c * MAT[j].c;
        if (cnd < min) min = cnd;
    }
    MEMO[i][j] = min;
    return min;
}
void input(void){
    scanf("%d", &N);
    for(int i = 0; i < N; i++) scanf("%d%d", &MAT[i].r, &MAT[i].c);
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
static const int Infinity=2000000000;

int main(){
    int n;cin>>n;
    int P[n+1],DP[n][n];
    rep(i,n){
        scanf("%d %d",&P[i],&P[i+1]);
    }
    rep(i,n){
        DP[i][i]=0;
    }
    for(int i=1;i<n;i++){
        for(int j=0;j+i<n;j++){
            int minc=Infinity;
            for(int k=j;k<j+i;k++){
                minc=min(minc,DP[j][k]+DP[k+1][j+i]+P[j]*P[k+1]*P[j+i+1]);
            }
            DP[j][j+i]=minc;
        }
    }
    cout<<DP[0][n-1]<<endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;

ll rec(int left, int right, vector<vector<ll> > &dp, vector<int> &R, vector<int> &C) {
    int N = dp.size();
    if (dp.at(left).at(right) != LLONG_MAX) {
        return dp.at(left).at(right);
    }
    if (left == right) {
        return dp.at(left).at(right) = 0;
    }
    ll res = LLONG_MAX;
    for (int i = left; i < right; ++i) {
        res = min(res, rec(left, i, dp, R, C) + rec(i + 1, right, dp, R, C) + 1LL * R.at(left) * C.at(i) * C.at(right));
    }
    return dp.at(left).at(right) = res;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N;
    cin >> N;
    vector<int> R(N), C(N);
    for (int i = 0; i < N; ++i) {
        cin >> R.at(i) >> C.at(i);
    }

    vector<vector<ll> > dp(N, vector<ll>(N, LLONG_MAX));

    cout << rec(0, N - 1, dp, R, C) << endl;

    return 0;
}