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
}

Python: import sys
input = sys.stdin.readline
n = int(input())
p0, p1 = map(int, input().split())
p = [p0, p1]
for _ in range(1, n):
    _, tmp = map(int, input().split())
    p.append(tmp)
# M[i]: p[i-1] * p[i]size

dp = [[0]*(n+1) for _ in range(n+1)]
#dp[i][j]: M[i]...M[j] の掛け算最小回数

for i in range(0, n+1):
    dp[i][i] = 0
# for i in range(1, n+1):
#     for j in range(i+1, n+1):
#         for k in range(i, j):
#             # M[i]...M[k], M[k+1]...M[j]
#             dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i-1]*p[k]*p[j])
# print(dp[1][n])

for w in range(2, n+1):
    for i in range(1, n+1):
        j = i+w-1
        if j >= n+1:
            continue
        res = 1e30
        for k in range(i, j):
            res = min(
                res,
                dp[i][k] + dp[k+1][j] + p[i-1] * p[k] * p[j]
            )
        dp[i][j] = res
print(dp[1][n])

Python: #!/usr/bin/env python3
# -*- coding: utf-8 -*-

import sys
import re
import math
import collections
import itertools
import functools

def dbg(*args):
    print("DBG: ", file=sys.stderr, end="")
    print(*args, file=sys.stderr)

Mat = collections.namedtuple("Mat", "r c")

def mat_mul(ms):
    return Mat(ms[0].r, ms[-1].c)

def cost(m1, m2):
    return m1.r * m1.c * m2.c

def solve(n, ms):
    if n == 1: return 0

    dp = {}
    for i in range(n):
        dp[(i,i)] = 0

    for l in range(2, n+1):
        for i in range(n-l+1):
            cost_min = math.inf
            #cost_min = float("inf")
            for j in range(l-1):
                dbg("l, i, j: %d %d %d", l, i, j)
                m_lhs = mat_mul(ms[i:i+j+1])
                m_rhs = mat_mul(ms[i+j+1:i+l])
                #dbg("m_lhs, m_rhs: %r %r", m_lhs, m_rhs)
                cost_lhs = dp[(i,i+j)]
                cost_rhs = dp[(i+j+1,i+l-1)]
                #dbg("cost_lhs, cost_rhs: %d %d", cost_lhs, cost_rhs)
                cost_mul = cost(m_lhs, m_rhs)
                #dbg("cost_mul: %d", cost_mul)
                cost_now = cost_mul + cost_lhs + cost_rhs
                #dbg("cost_now: %d", cost_now)
                if cost_min > cost_now:
                    cost_min = cost_now
            dp[(i,i+l-1)] = cost_min

    #dbg(dp)
    return dp[(0,n-1)]

def main():
    n = int(input())

    ms = []
    for _ in range(n):
        r,c = map(int, input().split())
        ms.append(Mat(r,c))

    print(solve(n, ms))

if __name__ == "__main__": main()

Python: # 連鎖行列積 Matrix chain multiplication

n = int(input())
p = [-1 for i in range(n + 1)]
M = [[-1 for i in range(n + 1)] for i in range(n + 1)]

for i in range(1, n + 1):
    l, m = (int(i) for i in input().split())
    p[i - 1] = l
    p[i] = m

for i in range(1, n + 1):
    M[i][i] = 0

for l in range(2, n + 1):
    for i in range(1, n - l + 2):
        j = i + l - 1
        M[i][j] = 2000000000
        for k in range(i, j):
            M[i][j] = min(M[i][j], M[i][k] + M[k + 1][j] + p[i - 1] * p[k] * p[j])

print(M[1][n])

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys


def mat_mul_opt(_mat_info):
    rc_info = list(map(int, _mat_info[0]))
    rc_info.extend(list(map(lambda x: int(x[1]), _mat_info[1:])))

    for l in range(2, mat_num + 1):
        for i in range(1, mat_num - l + 2):
            j = i + l - 1
            ans[i][j] = 1e7
            for k in range(i, j):
                ans[i][j] = min(ans[i][j], ans[i][k] + ans[k + 1][j] +
                                rc_info[i - 1] * rc_info[k] * rc_info[j])

    return ans[1][mat_num]


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    mat_num = int(_input[0])
    mat_info = tuple(map(lambda x: x.split(), _input[1:]))
    # assert len(mat_info) == mat_num

    ans = [[0] * (mat_num + 1) for _ in range(mat_num + 1)]
    print(mat_mul_opt(mat_info))

Python: n = int(input())
p = [0]*(n+1)

INF = 1000000000

for i in range(n):
    if i == 0:
        p[0],p[1] = map(int,input().split())
    else:
        tmp,p[i+1] = map(int,input().split())

dp = [[-1]*(n+2) for _ in range(n+2)]

def DFS(i,j):
    if dp[i][j] != -1:
        return dp[i][j]
    else:
        if j-i == 2:
            dp[i][j] = p[i]*p[i+1]*p[i+2]
            return dp[i][j]
        elif j-i == 1:
            dp[i][j] = 0
            return 0
        else:
            calculation_amount = INF
            for k in range(i+1,j):
                tmp = DFS(i,k) + DFS(k,j) + p[i]*p[j]*p[k] 
                calculation_amount = min(calculation_amount,tmp)
            dp[i][j] = calculation_amount
            return calculation_amount

print(DFS(0,n))