Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	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
			//kまでで区切る
			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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

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;
}

C++: #include <bits/stdc++.h>
#include <math.h>
#include <vector>
#include <queue>
#include <iomanip>
#include <string>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep_1 (i,j,n) for(int i=j;i<n;i++)
typedef long long ll;
typedef long l;
const ll l_INF = 1010101010101010;
const int INF = 1010101010;
const int dx[] = {-1,0,1,0,-1,-1,1,1};
const int dy[] = {0,-1,0,1,1,-1,1,-1};
ll dp[110][110];
ll m[2][110];

ll solve(int x,int y){
  if(dp[x][y]!=l_INF) return dp[x][y];
  ll ans=l_INF;
  for(int i=x+1;i<=y;i++){
    ans=min(ans,solve(x,i-1)+solve(i,y)+m[0][x]*m[1][i-1]*m[1][y]);
  }
  //cout<<ans<<endl;
  return dp[x][y]=ans;
}
int main(){
  int n; cin>>n;
  rep(i,n) cin>>m[0][i]>>m[1][i];
  rep(i,n)rep(j,n) dp[i][j]=l_INF;
  rep(i,n) dp[i][i]=0;
  rep(i,n-1) dp[i][i+1]=m[0][i]*m[0][i+1]*m[1][i+1];
  cout<<solve(0,n-1)<<endl;
}

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

using namespace std;

int main(void) {
	int n;
	cin >> n;
	vector< pair<int,int> > mat(n);
	for (int i = 0; i < n; ++i) {
		cin >> mat[i].first >> mat[i].second;
	}
	vector< vector<int> > dp(n,vector<int>(n,(1 << 28)));
	for (int i = 0; i < n; ++i) {
		dp[i][i] = 0;
	}
	for (int k = 1; k < n; ++k) {
		for (int i = 0; i < n-k; ++i) {
			for (int j = 0; j < k; ++j) {
				dp[i][i+k] = min(dp[i][i+j]+dp[i+j+1][i+k]+(mat[i].first*mat[i+j+1].first*mat[i+k].second),dp[i][i+k]);
			}
		}
	}
	cout << dp[0][n-1] << endl;
	return 0;
}

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

using namespace std;

template <class T>
T Vec(T v) { return v; }

template <class T, class... Ts>
auto Vec(size_t l, Ts... ts) {
    return vector<decltype(Vec<T>(ts...))>(l, Vec<T>(ts...));
}

const int INF = 1 << 30;

int N;
vector<int> deg;

int rec(int l, int r) {
    static auto dp = Vec<int>(N + 1, N + 1, -1);
    if (r - l <= 1) return 0;
    if (dp[l][r] >= 0) return dp[l][r];
    dp[l][r] = INF;

    for (int p = l + 1; p < r; ++p) {
        dp[l][r] = min(dp[l][r], rec(l, p) + rec(p, r) + deg[l] * deg[p] * deg[r]);
    }
    return dp[l][r];
}

int main() {
    cin >> N;

    deg.resize(N + 1);
    for (int i = 0; i < N; ++i) {
        int r, c;
        cin >> r >> c;
        deg[i] = r;
        if (i == N - 1) deg[i + 1] = c;
    }
    cout << rec(0, N) << endl;
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define lng long long
#define D(x) cout << #x " is " << x << endl

int n;
int rows[105];
int cols[105];
lng mem[105][105];

lng solve(int s, int e){
	if(s == e) return 0;
	
	lng &ret = mem[s][e];
	if(~ret) return ret;
	
	lng res = LLONG_MAX;
	lng curRes, cost;
	for(int i = s; i<e; i++){
		cost = 1LL*rows[s]*cols[i]*cols[e];
		curRes = cost + solve(s,i) + solve(i+1,e);
		res = min(res, curRes);
	}
	
	return ret = res;
}

int main(){
	// ios_base::sync_with_stdio(false);
	// cin.tie(NULL);
	// cout.tie(NULL);
	
	scanf("%d", &n);
	for(int i = 0; i < n; i++){
		scanf("%d%d", &rows[i], &cols[i]);
	}

	memset(mem, -1, sizeof mem);
	
	lng ans = solve(0, n-1);
	printf("%lld\n", ans);
	
	return 0;
}