Go: package main

/*
連鎖行列積
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

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

type mem *[][]int

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	p := make([]int, n+1)
	for i := 0; i < n; i++ {
		rowcol := eGetInts(scanner)
		p[i] = rowcol[0]
		p[i+1] = rowcol[1]
	}
	m := make([][]int, n)
	for i := 0; i < n; i++ {
		m[i] = make([]int, n)
	}
	// 初期値の格納
	for i := 0; i < n; i++ {
		for j := i; j < n; j++ {
			if i == j {
				m[i][j] = 0 //  同じ行列へのコストは当然0
			} else {
				m[i][j] = math.MaxInt64
			}
		}
	}

	// num : 行列の数. num == 1の場合は初期値0を格納ずみ
	for num := 2; num <= n; num++ {
		// s : スタート行列番号
		for s := 0; s+num <= n; s++ {
			// t : 終了行列番号
			t := s + num - 1
			// k : 仕切
			for k := s; k < t; k++ {
				m[s][t] = min(m[s][t], m[s][k]+m[k+1][t]+p[s]*p[k+1]*p[t+1])
			}
		}
	}
	fmt.Println(m[0][n-1])
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}

// func min(a []int) int {
// 	m := a[0]
// 	for _, v := range a {
// 		if v < m {
// 			m = v
// 		}
// 	}
// 	return m
// }

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: /*
* @Author: Samson
* @Date:   2018-06-11 12:09:01
* @Last Modified by:   Samson
* @Last Modified time: 2018-06-11 15:37:51
*/
//   @URL : http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_B
#include<bits/stdc++.h>
#include<algorithm>
#include <cstdlib>
#define INF 0x3f3f3f3f
using namespace std;
typedef long long LL;
const int MAXN = 1e5+10;

int p[205],f[105][105];

int main(void)
{
	ios::sync_with_stdio(false); 
	//cin.tie(0);
	int n;
	cin>>n;
	for(int i = 1; i <= n; ++i)
		cin>>p[i-1]>>p[i];
	memset(f,INF,sizeof f);
	for(int i = 1; i <= n; ++i)	f[i][i] = 0;
	for(int i = 2; i <= n; ++i)
	{
		for(int l = 1; l <= n-i+1; ++l)
		{
			int r = i+l-1;
			f[l][r] = INF;
			for(int k = l; k <= r-1; ++k)
				f[l][r] = min(f[l][r], f[l][k]+f[k+1][r]+p[l-1]*p[k]*p[r]);
		}
	}
	cout<<f[1][n]<<'\n';
	return 0;
}

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

template<typename T, typename U> void dmin(T &x, U y) { if(x > y) x = y; }

const int MAX_N = 100;
const int INF = 1001001001;

int main() {
  int n, r, c;
  int rc[MAX_N][2];
  cin >> n;
  for (int i=0; i<n; i++) {
    cin >> r >> c;
    rc[i][0] = r; rc[i][1] = c;
  }

  int dp[MAX_N][MAX_N];
  for (int i=0; i<n; i++) {
    for (int j=0; j<n; j++) {
      dp[i][j] = INF;
    }
    dp[i][i] = 0;
  }

  for (int l=2; l<=n; l++) {
    for (int i=0; i+l-1<n; i++) {
      for (int j=1; j<l; j++) {
        dmin(dp[i][i+l-1], dp[i][i+j-1] + rc[i][0]*rc[i+j-1][1]*rc[i+l-1][1] + dp[i+j][i+l-1]);
      }
    }
  }

  cout << dp[0][n-1] << endl;
  return 0;
}

C++: #include <cstdio>
#include <algorithm>
using namespace std;
const int M = 128;
const int inf = (1<<25);

int d[M][M], p[M+2];
int path[M][M];

int main()
{
	int n;
	scanf("%d", &n);
	for (int i = 0; i < n; ++i)
		scanf("%d %d", p+i, p+i+1);
	
	for (int i = 1; i <= n; ++i) d[i][i] = 0;
	for (int ln = 2; ln <= n; ++ln)	// 枚举矩阵链的长度 
	{
		int m = n - ln + 1; 		// 剩余矩阵的长度 
		
		for (int i = 1; i <= m; ++i)// len-ln = j-i+1 j = ln+i-1
		{
			int j = ln + i - 1;
			d[i][j] = inf;			
			for (int k = i; k < j; ++k)
				d[i][j] = min(d[i][j], d[i][k] + d[k+1][j] + p[i-1] * p[k] * p[j]);
		}		
	}
	
	printf("%d\n", d[1][n]);
	return 0;
}

C++: #include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<climits>
#include<iostream>
#include<sstream>
#include<utility>
#include<map>
#include<vector>
#include<queue>
#include<algorithm>
#include<set>
#include<stack>
using namespace std;
typedef long long ll;
typedef pair<int,int>P;
int N;
int r[105],c[105];
ll dp[105][105]={0};

void dbg()
{
	for(int i=0;i<N;i++,puts(""))
		for(int j=0;j<N;j++)
			printf("%7d ",dp[i][j]);
}

int main()
{
	scanf("%d",&N);
	for(int i=0;i<N;i++)
		scanf("%d%d",&r[i],&c[i]);
	for(int i=0;i<N;i++)dp[i][i]=0;
	for(int l=1;l<N;l++)
		for(int i=0;i<N-l;i++)
		{
			int j=i+l;
			dp[i][j]=1e15;
			for(int k=i;k<j;k++)
			{
				//printf("%d %d %d %d\n",i,j,i+l,k);
				dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+r[i]*c[k]*c[j]);
			}
		}
	//dbg();
	printf("%lld\n",dp[0][N-1]);
	return 0;
}

C++: #include<iostream>
using namespace std;
struct mat
{
	int w;
	int h;
};
typedef struct mat mat_t;
long long min(long long a,long long b);

int n;
mat_t a[101];
long long dp[101][101] ;

int main(){
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> a[i].h >> a[i].w;
	}
	for(int x = 0;x<n;x++){
		for(int y =0;y<n;y++){
			dp[x][y] = 2000000;
			if(x == y) dp[x][y] = 0;
		}
	}
	int i = 0;
	int j = 1;
	for(int l = 1;l<n;l++){
		i = 0;
		for(j=l;j<n;j++){
			for(int k = i;i <= k && k < j;k++){
				dp[i][j] = min(dp[i][j],dp[i][k] + dp[k+1][j] + a[i].h *a[k].w * a[j].w);
			}
			i++;
		}
	}
	cout << dp[0][n-1] << endl;
}

long long min(long long a,long long b) {
	return a<b? a:b;
}