Go: package main

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

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, v
	}
	if len(matrices) == 0 {
		panic("must not be empty")
	} else if len(matrices) == 1 {
		return matrices[0], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < len(matrices)-1; i++ {
		formerMatrices := matrices[:i+1]
		latterMatrices := matrices[i+1:]
		matF, countF := calcMinMatrixChainMultiplication(formerMatrices, Range{0, i}, memo)
		matL, countL := calcMinMatrixChainMultiplication(latterMatrices, Range{i + 1, len(matrices) - 1}, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

Python: import sys
input = sys.stdin.readline

def matrixChainMultiplication(n):
    for l in range(2, n+1):
        for i in range(1, n-l+2):
            j = i + l - 1
            min_ = 2**21 # 十分大きい数
            for k in range(i, j):
                value = m[i][k] + m[k+1][j] + p[i-1]*p[k]*p[j]
                if min_ > value:
                    min_ = value
            m[i][j] = min_

m = [[0]*(101) for _ in range(101)]
p = [0] * 101
N = int(input())
l0 = list(map(int, input().split()))
p[0] = l0[0]
p[1] = l0[1]
for _ in range(1, N):
    li = list(map(int, input().split()))
    p[_+1] = li[1]
matrixChainMultiplication(N)
print(m[1][N])

Python: def chain(p,n):
    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] = 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])

p={}
n = int(input())
for i in range(1,n+1):
    st = input()
    w = st.split()
    p[i-1] = int(w[0])
    p[i]   = int(w[1])
chain(p,n)

Python: import sys
sys.setrecursionlimit(10**7)
debug = False
import numpy as np
def dprint(*objects):
    if debug == True:
        print(*objects)

# n = int(input())
# a, b = map(int, input().split())
# int_list = list(map(int, input().split()))
# l = list(input().split())



def solve():
    n = int(input())
    mat_list = []
    for i in range(n):
        mat_list.append(list(map(int, input().split())))
    dprint(mat_list)

    # 掛け始めのidxと掛け終わりのidxをi, jとし、計算回数を持つメモ
    memo = np.zeros(shape=(n, n))

    def calc(start, end):
        dprint("*", start, end)
        # 1つの行列なら0
        if end == start:
            return 0

        # メモがあれば返す
        if memo[start][end] != 0:
            return memo[start][end]

        # 2つの行列なら、答えを計算しメモ追記
        if end - start == 1:
            cost = mat_list[start][0] * mat_list[start][1] * mat_list[end][1]
            memo[start][end] = cost
            dprint(start, end, cost)
            return cost

        # 3つ以上なら、再帰
        min_cost = -1
        if end - start >= 2:
            for right_start in range(start+1, end+1):
                left = calc(start, right_start-1)
                right = calc(right_start, end)
                cost = left + right + mat_list[start][0] * mat_list[right_start][0] * mat_list[end][1]
                if min_cost == -1 or min_cost > cost:
                    min_cost = cost
                dprint(start, end, right_start, min_cost, cost)

        memo[start][end] = min_cost
        return min_cost

    ans = calc(0, n-1)
    dprint(memo)
    print(int(ans))

solve()

Python: #!/usr/bin/env python3
import sys
input = lambda: sys.stdin.readline()[:-1]
sys.setrecursionlimit(10**8)




n=int(input())
M=[0]*(n+1)
for i in range(n):
    M[i],M[i+1]=map(int,input().split())
dp=[[float('inf')]*n for i in range(n)]
for i in range(n):
    dp[i][i]=0
for k in range(1,n):
    for i in range(n-k):
        j=i+k
        for l in range(i,j):
            dp[i][j]=min(dp[i][j],dp[i][l]+dp[l+1][j]+M[i]*M[l+1]*M[j+1])
print(dp[0][n-1])
# print(dp)

Python: def matrix_chain_multiplication(n, list):
    matrix = [[0 for i in range(n)] for j in range(n)]

    for i in range(n-1):
        for j in range(n-i-1):
            k = j+i+1
            matrix[j][k] = float('inf')
            for r in range(j, k):
                matrix[j][k] = min(matrix[j][k],
                    matrix[j][r] + matrix[r+1][k]
                    + list[j]*list[r+1]*list[k+1])

    return matrix[0][n-1]

if __name__ == '__main__':
    n = int(input())

    list = list(map(int, input().split()))
    for i in range(n-1):
        list.append(int(input().split()[1]))

    print(matrix_chain_multiplication(n, list))

Python: import sys
input = sys.stdin.readline
INF = 1001001001001001
def main():
    n = int(input())
    p = [0] * (n+1)
    for i in range(n):
        p[i], p[i+1] = map(int, input().split())
    dp = [[INF]*(n+1) for _ in range(n+1)]
    for i in range(n+1):
        dp[i][i] = 0
    for l in range(2, n+1):
        for i in range(n-l+2):
            j = i + l - 1
            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])
    print(dp[1][n])
if __name__ == '__main__': main()

Python: n = int(input())
p = list(range(n+2))

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

# table[i][j] : M_i??????M_j??????????????????????°?????????°
table = [[0] * (n+1) for i in range(n+1)]

# ??£????????£???2????????????????????????
for i in range(1,n):  # 1<=i,i+1<=n
    table[i][i+1] = p[i]*p[i+1]*p[i+2]


for k in range(3, n+1):    # ?????????k???????????????????????????3<=k<=n
    for i in range(1,n+2-k): # M_i?????????1<=i<=n-k+1
        j = i + k - 1      # M_j?????§???k??????

        table[i][j] = float('inf')

        for x in range(i, j): # M_i~M_x??¨M_(x+1)~M_j??§????????????(i<=x,x+1<=j<=n)
            print(i, x, j)
            cost = table[i][x] + table[x+1][j] + p[i]*p[x+1]*p[j+1]
            table[i][j] = min(table[i][j], cost)
            

print(table[1][n])