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 <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;
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define MAX 100
int min(int,int);
int p[MAX+1]={},m[MAX+1][MAX+1]={};

int min(int n1,int n2){
  if(n1>n2) return n2;
  else return n1;
}

int main()
{
  int n,l,i,j,k;
  
  scanf("%d",&n);
  
  for(i=1;i<=n;i++){
    scanf("%d %d",&p[i-1],&p[i]);
  }
  
  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]);
      }
    }
  }
  
  printf("%d\n",m[1][n]);
  
  return 0;
}

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

int main()
{
	int n;
	int v[101];
	long m[100][100];
	const long nil = 999999999;

	cin >> n;

	for (int i = 0; i < n; i++)
		cin >> v[i] >> v[i + 1];

	for (int i = 0; i < 100; i++)
		for (int j = 0; j < 100; j++)
			if (i == j)
				m[i][j] = 0;
			else
				m[i][j] = nil;
	
	for(int i = n - 2; i > -1; i--)
		for(int j = i + 1; j < n; j++)
			for (int k = i; k < n; k++)
				m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + v[i] * v[k + 1] * v[j + 1]);

	cout << m[0][n - 1] << endl;

	return 0;
}

C++: #include <cstdio>

int main(void) {
    int n, u, k, v, i, j;
    scanf("%d", &n);
    int m[n+1][n+1];

    for (i = 1; i <= n; i++)
        for (j = 1; j <= n; j++)
            m[i][j] = 0;

    for (i = 0; i < n; i++) {
        scanf("%d %d", &u, &k);
        for (j = 0; j < k; j++) {
            scanf("%d", &v);
            m[u][v] = 1;
        }
    }

    for (i = 1; i <= n; i++) {
        for (j = 1; j <= n; j++) {
            if (j-1) printf(" ");
            printf("%d", m[i][j]);
        }
        printf("\n");
    }

    return 0;
}

C++: #include<cstdio>
#include<algorithm>
using namespace std;
static const int N=100;
int main(){
  int n,p[N+1],m[N+1][N+1];
  scanf("%d",n);;
  for(int i=1;i<=n;i++)
    scanf("%d%d",&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-1+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]);
      }
    }
  }
  printf("%d\n",m[1][n]);
  return 0;
}