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 <iostream>
#include <array>
#include <limits>

using namespace std;

struct MatrixDims {
    int row;
    int col;
    MatrixDims() {}
    MatrixDims(int row, int col) : row(row), col(col) {}
};

array<MatrixDims, 100> matrix_dims;
array<array<int, 100>, 100> dp;

int get_min(int row, int col) {
    int min = numeric_limits<int>::max();
    for (int j = row; j < col; ++j) {
        int sum = dp[row][j] + dp[j+1][col] + matrix_dims[row].row * matrix_dims[j].col * matrix_dims[col].col;
        if (sum < min) min = sum;
    }
    return min;
}

int main()
{
    int n;
    cin >>  n;
    for (int i = 0; i < n; ++i) {
        int row, col;
        cin >> row >> col;
        matrix_dims[i] = MatrixDims(row, col);
    }
    dp.fill({});
    
    for (int endpt = 1; endpt < n; ++endpt) {
        for (int diag_i = 0; (endpt + diag_i) < n; ++diag_i) {
            dp[diag_i][diag_i + endpt] = get_min(diag_i, endpt + diag_i);
        }
    }
    cout << dp[0][n-1] << endl;
}

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

static const long N = 100;

int main(){
	long n, p[N + 1], m[N + 1][N + 1];
	cin >> n;
	for (long i = 1; i <= n; i++){
		cin >> p[i - 1] >> p[i];
	}

	for (long i = 1; i <= n; i++) m[i][i] = 0;
	for (long l = 2; l <= n; l++){
		for (long i = 1; i <= n - l + 1; i++){
			long j = i + l - 1;
			m[i][j] = (1 << 21);
			for (long 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<stdio.h>
#include<map>
#include<array>

using lr = std::pair<int, int>;
using lr_map = std::map<lr, int>;

int rc(int mat[], lr_map &dp, int n, int rest_n, int limit);

int main()
{
	int n, mat[101]{}, count{};
	lr_map dp;

	scanf("%d%d%d", &n, mat, mat + 1);
	for (int i = 1; i < n; ++i)
		scanf("%d%d", mat + i, mat + i + 1);

	printf("%d\n", rc(mat, dp, 0, n, 2000000000));

	return 0;
}

int rc(int mat[], lr_map &dp, int left, int right, int min)
{
	if (left + 1 == right) return 0;
	if (dp.find(lr{ left, right }) != dp.end()) return dp[lr{ left, right }];

	for (int mid = left + 1; mid < right; ++mid)
	{
		int tmp = mat[left] * mat[mid] * mat[right];
		tmp += rc(mat, dp, left, mid, min);
		if (tmp > min) continue;

		tmp += rc(mat, dp, mid, right, min);
		if (tmp > min) continue;

		min = tmp;
	}
	dp[lr{ left, right }] = min;
	return min;
}

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#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 <cstdio>
#include <algorithm>
using namespace std;
int m[107], dp[107][107];
int main() {
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
    	scanf("%d%d", &m[i], &m[i + 1]);
	}
	for (int l = 2; l <= n; l++) {
		for (int i = 1; i <= n - l + 1; i++) {
			int j = i + l - 1;
			dp[i][j] = 1e9 + 7;
			for (int k = i; k < j; k++) {
				dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + m[i - 1] * m[k] * m[j]);
			}
		}
	}
	printf("%d\n", dp[1][n]);
    return 0;
}

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

int main(){
	int n, p[101],m[101][101];
	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;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 <climits>
#include <iostream>
#include <vector>

struct TMatrix
{
	int Row;
	int Col;
	
	TMatrix(int ARow, int ACol);
};

TMatrix::TMatrix(int ARow, int ACol)
: Row(ARow), Col(ACol)
{
}

class TMinimumMultiplications
{
	std::vector<std::vector<int> > FTable;
	const std::vector<TMatrix>& FMatrixChain;
	
	int GetMinimum(int Begin, int End);
public:
	TMinimumMultiplications(const std::vector<TMatrix>& MatrixChain);
	
	int Get(int Begin, int End);
};

TMinimumMultiplications::TMinimumMultiplications(const std::vector<TMatrix>& MatrixChain)
: FMatrixChain(MatrixChain), FTable(MatrixChain.size(), std::vector<int>(MatrixChain.size(), -1))
{
}

int TMinimumMultiplications::GetMinimum(int Begin, int End)
{
	int Minimum = INT_MAX;
	for(int i = Begin; i < End; ++i){
		int Total = Get(Begin, i)
		          + Get(i + 1, End)
		          + FMatrixChain[Begin].Row * FMatrixChain[i + 1].Row * FMatrixChain[End].Col;
		if(Minimum > Total) Minimum = Total;
	}
	return Minimum;
}

int TMinimumMultiplications::Get(int Begin, int End)
{
	if(Begin == End) return 0;
	if(FTable[Begin][End] < 0){
		FTable[Begin][End] = GetMinimum(Begin, End);
	}
	return FTable[Begin][End];
}

int MinimumMultiplicationCount(const std::vector<TMatrix>& MatrixChain)
{
	TMinimumMultiplications Minimum(MatrixChain);
	return Minimum.Get(0, MatrixChain.size() - 1);
}

int main()
{
	int Count;
	std::cin >> Count;
	std::vector<TMatrix> MatrixChain;
	for(int i = 0; i < Count; ++i){
		int Row, Col;
		std::cin >> Row >> Col;
		MatrixChain.push_back(TMatrix(Row, Col));
	}
	
	std::cout << MinimumMultiplicationCount(MatrixChain) << std::endl;
	return 0;
}