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 <algorithm>
using namespace std;
static const int A=100;
int main(){
    int n,p[A+1],m[A+1][A+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 j=2; j<=n; j++){
        for(int i=1;i<=n-j+1;i++){
        int l=i+j-1;
        m[i][l]=(1<<21);
        for(int x=i;x<=l-1;x++){
            m[i][l]=min(m[i][l],m[i][x]+m[x+1][l]+p[i-1]*p[x]*p[l]);
        }
        }
    }
cout<<m[1][n]<<endl;
return 0;
}

C++: #include <iostream>

using namespace std;

int main() {
  // 初期化
  int n;
  cin >> n;
  int m[110][110];
  int p[110];
  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;
}

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 >> 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;

   return0;
}

C++: #include<stdio.h>

int matrixChainOrder(int *p);
int m[101][101];
int n1;
int main(){
  
  int i,r,c,min;
  int p[100];
  scanf("%d",&n1);

  for(i=0;i<n1;i++){
    scanf("%d %d",&r,&c);
    if(i==n1-1) p[n1]=c;
    p[i]=r;
  }

  min = matrixChainOrder(p);
  printf("%d\n",min);

  return 0;
}

int matrixChainOrder(int *p){
  int n2,l,i,j,q,k;
  
  n2 = n1 - 1;
  for(i=1;i<=n2;i++){
    m[i][i] = 0;
  }
  for(l=2;l<=n2;l++){ 
    for(i=1;i<=n2-l+1;i++){ 
      j = i+l-1;
      m[i][j] = 1.0/0.0;
      for(k=i;k<j;k++){
	q = m[i][k] + m[k+1][j]+p[i-1]*p[k]*p[j];
        if(m[i][j]>=q)  m[i][j] = q;
      }
    }
  }
  return m[i][j];
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
#define N (100)

int main(void){
    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=0;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 <stdio.h>

#define MAX_N 100
#define INF 1e8

int main(){
  int N,i,j,k,l,q,r[MAX_N],c[MAX_N],p[MAX_N+1];
  int dp[MAX_N+1][MAX_N+1];
  scanf("%d",&N);
  for(i = 0 ; i < N ; i++){
    scanf("%d%d",&r[i],&c[i]);
  }
  p[0] = r[0];
  for(i = 1 ; i <= N ; i++){
    p[i] = c[i-1];
  }
  N++;
  for(i = 0 ; i < N ; i++){
    dp[i][i] = 0;
  }
  for(l = 2 ; l < N ; l++){
    for(i = 1 ; i < N-l+1 ; i++){
      j = i + l - 1;
      dp[i][j] = INF;
      for(k = i ; k <= j-1 ; k++){
        q = dp[i][k] + dp[k+1][j] + p[i-1]*p[k]*p[j];
        if(q < dp[i][j]){
          dp[i][j] = q;
        }
      }
    }
  }
  printf("%d\n",dp[1][N-1]);
  return 0;
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <cctype>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <functional>
 
using namespace std;
using ll = long long int;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)

#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
#define itn ll
#define int ll
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
///                →,↑,←,↓,↗,↖,↙,↘
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };
 
 static const int N = 100;

signed main() {
    ios::sync_with_stdio(false);
    int n,p[N + 1],m[N+1][N+1];
    cin>> n;
    int i;
    FOR(i,1,n+1){
        cin >> p[i-1] >> p[i];
    }
    FOR(i,1,n+1) m[i][i] = 0;
    for(int l = 2; l <= n; l++){
        for(int i = 1; i <= n -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] << '\n';
    return 0;
}

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

using namespace std;

static const int N=100;

int main(){
  int n,i,l,j,k,p[N+1],m[N+1][N+1];
  cin>>n;

  for(i=1;i<=n;i++){
    cin>>p[i-1]>>p[i];
  }

  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]=(1<<21);
          for(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 <bits/stdc++.h>
#define N 101
using namespace std;
int A[N];

int dp[N][N];

int Min(int &a,int b){return a = min(a,b);}

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

  for(int i=0,cnt=0;i<n;i++){
    int a,b;
    cin>>a>>b;
    if(i == 0) A[cnt++] = a;
    A[cnt++] = b;
  }

  for(int i=0;i<n+1;i++){
    for(int j=0;j<n+1;j++)dp[i][j] = 1e9;
    dp[i][i] = 0;
  }
  
  for(int len=0;len<n;len++)
    for(int l=1;l<n;l++){
      int r = l+len;
      for(int m = l;m<r;m++){
        Min(dp[l][r],dp[l][m] + dp[m+1][r] + A[l-1]*A[m]*A[r]);
      }
}
  
  cout<<dp[1][n]<<endl; 
  return 0;
}