Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	fmt.Println(resolve(parseProblem()))
}

type matrixSize struct{ row, col int }

func calcNum(i, j matrixSize) int {
	return i.row * j.col * i.col
}

func parseProblem() (int, []matrixSize) {
	n := scanInt(sc)
	sizes := make([]matrixSize, n)
	for i := 0; i < n; i++ {
		sizes[i] = matrixSize{row: scanInt(sc), col: scanInt(sc)}
	}
	return n, sizes
}

var dp [][]int

func initDP(n int) {
	dp = make([][]int, n+1)
	for i := 0; i < len(dp); i++ {
		dp[i] = make([]int, n+1)
		for j := 0; j < len(dp[i]); j++ {
			dp[i][j] = math.MaxInt64
		}
	}
}

func resolve(n int, sizes []matrixSize) int {
	// TODO 復習
	initDP(n)
	_rec(sizes, 0, n)
	return dp[0][n]
}

func _rec(sizes []matrixSize, l, r int) int {
	if dp[l][r] != math.MaxInt64 {
		return dp[l][r]
	}
	if r-l <= 1 {
		dp[l][r] = 0
		return 0
	}
	num := math.MaxInt64
	for i := l + 1; i < r; i++ {
		v := _rec(sizes, l, i) + _rec(sizes, i, r) + calcNum(matrixSize{sizes[l].row, sizes[i].row}, matrixSize{sizes[i].row, sizes[r-1].col})
		if v < num {
			num = v
		}
	}
	dp[l][r] = num
	return dp[l][r]
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

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

logging.basicConfig(level=logging.DEBUG, format="DBG: %(message)s")

def dbg(msg, *args, **kwargs):
    logging.debug(msg, *args, **kwargs)

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: n = int(input())
r=[0]*(n+1)
c=[0]*(n+1)
for i in range(n):
    r[i+1], c[i+1] = map(int, input().split())

dp = [[float('inf') for i in range(n+1)] for j in range(n+1)]

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

# print("")
for l in range(2, n+1):
    for i in range(1, n-l+2):
        # print("l=", l, "i=", i)
        tmp_list = [r[i] * c[i+l-1] * r[j+1] + dp[i][j] + dp[j+1][i+l-1] for j in range(i, i+l-1)]
        dp[i][i+l-1] = min(tmp_list)

print(dp[1][n])

Python: n=int(input())+1
e=[input().split()for _  in[0]*~-n]
p=[int(e[0][0])]+list(int(x[1])for x in e)
m=[[0]*n for _ in[0]*n]
for l in range(2,n):
 for i in range(1,n-l+1):
  j=i+l-1;m[i][j]=1e6
  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-1])

Python: n = int(input())
p = [0] * (n + 1)
m = [[0 for _ in range(100)] for _ in range(100)]

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

for l in range(2, n + 1):
    for i in range(1, n - l + 2):
        j = i + l - 1
        m[i][j] = float('inf')
        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: def s():
 n=int(input())+1
 e=[input().split()for _  in[0]*~-n]
 p=[int(e[0][0])]+list(int(x[1])for x in e)
 m=[[0]*n for _ in[0]*n]
 for i in range(n):
  for r in range(n-i-1):
   c=r+i+1
   for j in range(r+1,c):
    x=m[r][j]+m[j][c]+p[r]*p[j]*p[c]
    if not 0<m[r][c]<=x:m[r][c]=x
 print(m[r][c])
if'__main__'==__name__:s()

Python: def s():
 n=int(input())+1
 e=[input().split()for _  in[0]*~-n]
 p=[int(e[0][0])]+list(int(x[1])for x in e)
 m=[[0]*n for _ in[0]*n]
 for i in range(n):
  for r in range(n-i-1):
   c=r+i+1
   for j in range(r+1,c):
    x=m[r][j]+m[j][c]+p[r]*p[j]*p[c]
    if 1>m[r][c]or m[r][c]>x:m[r][c]=x
 print(m[r][c])
if'__main__'==__name__:s()

Python: N = int(input())
P = []
for i in range(N):
    r, c = map(int, input().split())
    if i == 0:
        P.append(r)
    P.append(c)


def matrix_chain():
    dp = [[None for j in range(N+1)] for i in range(N+1)]
    for i in range(1, N+1):
        dp[i][i] = 0

    for l in range(2, N+1):
        for i in range(1, N-l+2):
            j = i + l - 1
            dp[i][j] = 1000000000000000
            for k in range(i, j):
                dp[i][j] = min(dp[i][j], dp[i][k]+dp[k+1][j]+P[i-1]*P[k]*P[j])

    return dp[1][N]


def main():
    print(matrix_chain())


if __name__ == '__main__':
    main()

Python: #!/usr/bin/env python
from __future__ import division, print_function
from sys import stdin


def main():
    num_mat = int(stdin.readline())
    r = [int(s) for s in stdin.readline().split()]
    for _ in range(num_mat-1):
        _, row = (int(s) for s in stdin.readline().split())
        r.append(row)

    if num_mat < 2:
        print(0)
        return
    elif num_mat < 3:
        print(r[0]*r[1]*r[2])
        return

    M = []
    M.append([0] * num_mat)
    M.append([r[i]*r[i+1]*r[i+2] for i in range(len(M[-1])-1)])

    for i in range(2, num_mat):
        N = []
        for j in range(num_mat-i):
            N.append(min(M[k][j]+M[i-1-k][1+j+k]+r[j]*r[1+j+k]*r[i+1+j]
                         for k in range(i)))
        M.append(N)
    print(M[-1][0])


main()

Python: # https://onlinejudge.u-aizu.ac.jp/courses/lesson/1/ALDS1/10/ALDS1_10_B
# 普通に難しい
# アイデアは写真の解説を参照

# データの入力
N = int(input())

for i in range(N):
    if i == 0:
        P = list(map(int, input().split()))
        continue
    P.append(int(input().split()[1]))

# dpテーブルの用意 minを取るときはinf埋めしておくと処理が楽になるしバグが見つかりやすい
INF = 2**32-1
dp = [[INF]*N for _ in range(N)]

# dpテーブルの初期化
# 対角成分0
for ij in range(N):
    dp[ij][ij] = 0

# dpの更新 どう更新しているのか、なんでこう更新するのかは写真を参照
for l in range(1, N):  # lは対角成分からいくつ離れているか (なん個行列をかけるかという解釈も可)
    for i in range(N):
        j = i+l
        if j >= N:
            continue
        for k in range(i, j):
            dp[i][j] = min(dp[i][k] + dp[k+1][j] + P[i]
                           * P[j+1]*P[k+1], dp[i][j])
# from pprint import pprint
# pprint(dp)
print(dp[0][-1])