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++: ////////////////////////////////////////
//ALDS1_9_A:   Complete Binary Tree
//ALDS1_9_B:   Maximum Heap
//ALDS1_9_C:   Priority Queue
////////////////////////////////////////

#include <iostream>
#include <algorithm> // next_permutation
#include <iomanip>
#include <cmath>
#include <vector>
#include <sstream>
#include <string>
#include <cstdio>
#include <stack>
#include <queue>
#include <list>
#include <numeric> //accumulate
//#include <unordered_map> //???????????\??¢??°
#include <fstream> //ifstream, ofstream

//#define NDEBUG //NDEBUG???#include <cassert>???????????????????????????????????´???assert?????????????????????????????????NDEBUG?????????????????????????????????????????????
#include <cassert> //assert


using namespace std;

//???????????°??????TEST????????????????????¬???????????????????????????????????¢????????????
#define TEST //*******************************************************************************************************************************************
//?????????????????¨??§?????\????????????????????????????????°?????????????¨???????????????????dout???????????????????????§???????????¬??????????????????????????????????????????
//??????????????????????????????????????????????????????????§?CPU???????£??????????????????§???TLE?????????????????????????????????????????§????????¨???                           ????????????????????????cerr????????£????????????????????????????????????
#ifdef TEST
#define dout cout
#define din cin
#else
stringstream dummy; //???????????°??????dout?????????????????????????????????
#define dout dummy.str(""); dummy.clear(stringstream::goodbit); dummy //dummy?????????????????????????????????????????¨?????¢?????¢???????????????
//???????????¨??????????????????goodbit?????????????????????????????¨???????????´????????????????????????????????¨?????°?????????????????§???????????????????????????????????? http://d.hatena.ne.jp/linden/20060427/p1
#endif

//?¨??????????????????????????????????????????????????????´??????OUTPUTFILE????????????????????¬???????????????????????????????????¢????????????
//#define OUTPUTFILE "output.txt" //*******************************************************************************************************************************************
#ifdef OUTPUTFILE
#define dout outputfile //??¨????????????TLE????????§?????????dout?????¨??¨??????????????¢????????????????????????????????????????????§????¨????????????´??????????????£??????????????????????¨?????????????????????????????????????????????§?????????????????????
ofstream outputfile(OUTPUTFILE);
#define OutputFilePath "/Users/Nag/Documents/Prgm/Test/DerivedData/Test/Build/Products/Debug/output.txt"
#endif

//?¨??????\???????????????????????????????????????????????´??????INPUTFROMTEXTFILE????????????????????¬???????????????????????????????????¢????????????
//#define INPUTFILE "input.txt" //*******************************************************************************************************************************************
#ifdef INPUTFILE
#define din inputfile
ifstream inputfile(INPUTFILE);
#endif


#define disp(A) dout << #A << " = " << (A) << endl
#define disP(A) dout << setw(3) << (A) << " " // << setw(3) ??????????????\????????????
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)

#define dispAll(A,n) dout << #A << " = "; rep(j, 0, (n)) {disP(A[j]);} dout << endl

typedef pair<int,int> pii;
typedef vector<int> vi;
typedef unsigned long long ll;

const int INF = 1e9-1;

int N;
const int N_MAX = 100;
int m[N_MAX+2];
int dp[N_MAX][N_MAX]; //dp[i][j] = ??????M[i]??????M[j]?????§????????????????±?????????¨???????????????????????????????°??????°

int main() {
    din >> N;
    int r, c;
    rep(i,0,N) {
        cin >> r >> c;
        if(i==0) m[i] = r, m[i+1] = c;
        else m[i+1] = c;
    }
    
//    dispAll(m, N+1);
    
    rep(i,0,N) {
        rep(j,0,N) {
            if(i==j) dp[i][j] = 0;
            else dp[i][j] = INF;
        }
    }
    
    
//    //test display
//    dout<<"-----------------------------\n";
//    dout<<"        j = ";
//    rep(j,0,N) disP(j);
//    dout<<endl;
//    rep(i,0,N) {
//        disP(i);
//        dispAll(dp[i], N);
//    }
    
    //calc.
    rep(x,1,N) {
//        disp(x);
        rep(i,0,N-x) {
            int j = x+i;
//            disp(i); disp(j);
            rep(k,i,j) {
//                disp(k);
//                disp(m[i]*m[k+1]*m[j+1]);
                
                assert(dp[i][k]!=INF);
                assert(dp[k+1][j]!=INF);
                
                dp[i][j] = min( dp[i][j], dp[i][k]+dp[k+1][j]+m[i]*m[k+1]*m[j+1] );
            }
            
//            //test display
//            dout<<"        j = ";
//            rep(j,0,N) disP(j);
//            dout<<endl;
//            rep(i,0,N) {
//                disP(i);
//                dispAll(dp[i], N);
//            }
//            dout<<"-----------------------------\n";
        }
    }
    
    
    dout << dp[0][N-1] << endl;
    
    
    
    
#ifdef INPUTFILE
    inputfile.close();
#endif
    
#ifdef OUTPUTFILE
    outputfile.close();
    cout << "\"" << OutputFilePath << "\"" << endl;
#endif
    
    return 0;
}

C++: #include<bits/stdc++.h>
#define MAX 110
#define INF 100000000
using namespace std;

int main(){
    int n,p[MAX],i,j,l,k,q;
    int m[MAX][MAX]={};
    cin>>n;
    for(i=0;i<n;i++)cin>>p[i]>>p[i+1];
    for(i=1;i<=n;i++)m[i][i]=0;
    for(l=2;l<=n;l++){
        for(i=1;i<=n-l+1;i++){
            j=i+l-1;
            m[i][j]=INF;
            for(k=i;k<j;k++){
                q=m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j];
                m[i][j]=min(m[i][j],q);
            }
        }
    }
  cout<<m[1][n]<<endl;
}

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

static const int N = 105;

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;

}