https://projecteuler.net/problem=16
Problem 13のBigIntegerに掛け算を付け加えただけです。
from math import max import sys #################### BigInteger #################### struct BigInteger(CollectionElement): var v: DynamicVector[Int] fn __init__(inout self, v: DynamicVector[Int]): self.v = v fn __copyinit__(inout self, other: BigInteger): self.v = other.v fn __moveinit__(inout self, owned other: BigInteger): self.v = other.v^ fn __add__(self, other: BigInteger) -> BigInteger: var v = DynamicVector[Int]() var carry = 0 for i in range(max(self.v.size, other.v.size)): let d1 = self.v[i] if i < self.v.size else 0 let d2 = other.v[i] if i < other.v.size else 0 let n = d1 + d2 + carry let d = n % 10 v.push_back(d) carry = n // 10 if carry > 0: v.push_back(carry) return BigInteger(v) fn __mul__(self, other: Int) -> BigInteger: var v = DynamicVector[Int]() var carry = 0 for i in range(self.v.size): let n = self.v[i] * 2 + carry let d = n % 10 v.push_back(d) carry = n // 10 if carry > 0: v.push_back(carry) return BigInteger(v) fn __str__(self) -> String: var s: String = "" for i in range(self.v.size-1, -1, -1): s += String(self.v[i]) return s @staticmethod fn create(n: Int) -> BigInteger: var v = DynamicVector[Int]() v.push_back(n) return BigInteger(v) @staticmethod fn parse(s: String) -> BigInteger: var v = DynamicVector[Int]() for i in range(len(s)-1, -1, -1): v.push_back(ord(s[i]) - 48) return BigInteger(v) #################### process #################### fn sum(v: DynamicVector[Int]) -> Int: var s: Int = 0 for i in range(v.size): s += v[i] return s fn f(N: Int) -> Int: var n = BigInteger.create(1) for i in range(N): n = n * 2 return sum(n.v) fn main() raises: let args = sys.argv() let N = atol(args[1]) print(f(N))
