**Diary Entry**
The divorce crushed Marina like a steamroller. She’d adored her husband and never expected betrayal, least of all from him. But he cheated—with her best friend. In one day, she lost both people she’d trusted with her heart. Her faith in men shattered. She’d always brushed off warnings that “all men cheat,” insisting, “My Daniel’s different.” Now, the betrayal scorched her from within, and she vowed never to open her heart again.
Marina raised her daughter, Lucy. Her ex paid child support on time and saw the girl occasionally but had no real interest in fatherhood. Marina resigned herself to loneliness—even found bitter comfort in it. A life without a man seemed simpler. But fate loves ruining plans.
At a colleague’s birthday in a cosy café in Bristol, Marina met Andrew, the birthday girl’s brother. He’d also survived divorce, and to her surprise, his son, Oliver, lived with him, not his mother. Andrew explained: the boy had chosen him, and his ex-wife, wrapped up in a new romance, hadn’t protested. A teenager was just baggage to her.
That evening stirred forgotten warmth in Marina. Like a schoolgirl, she felt butterflies—a feeling she hadn’t known in years. Andrew was equally smitten. Both bruised by divorce, they feared new emotions, but the spark between them was undeniable.
Andrew coaxed his sister for Marina’s number and, mustering courage, called. Avoiding the word “date” (absurd at their age), he suggested meeting to talk. They went to a quiet pub, talked until closing time, losing track of the hours. Then came another meet-up, and another.
One weekend, Lucy stayed with her father, and Marina invited Andrew over. That night sealed it—they didn’t want to part again. Their love, tender and mature, felt like redemption. But one obstacle remained: the children.
Both had teens. Oliver, Andrew’s son, was a year older than Lucy. Different personalities, interests, friends. At first, Marina and Andrew just dated, occasionally bringing the kids along, but it was clear: Lucy and Oliver weren’t just indifferent—they barely hid their dislike.
After a year and a half, Andrew couldn’t take it. He proposed. He loved her so fiercely it made him feel like a boy again, but he wanted a real family, not the hollow shell of his first marriage. Secret calls and stolen nights weren’t enough. Marina, stunned, said yes. She wanted to wake up beside him, cook breakfast together, watch films at night.
They planned it all. Their flats were too small—teens of opposite sexes needed separate rooms. Selling both and adding Andrew’s savings, they bought a spacious house in the Cotswolds. The hardest part remained: telling the kids.
They broke the news separately to soften the blow. “I don’t want to live with Andrew and Oliver!” Lucy fumed. “Why do you need a wedding and this house?” Marina’s heart ached for her—Lucy would have to adjust for her sake. But in a few years, Lucy would leave the nest, and what then? Emptiness? She knew mothers who’d sacrificed everything, only to demand the same from their children. Marina refused that fate. Gently but firmly, she said, “It’s decided. But I’ll always listen, and you’ll always come first.”
Lucy sulked but didn’t argue. Her father, recently remarried, barely called anymore, and she felt abandoned. After a long talk, she grudgingly agreed, trusting her mother wouldn’t betray her.
Andrew’s conversation was just as rough. “Why should I live with some girl and her mum?” Oliver grumbled. “Because I love Marina,” Andrew replied calmly. “Then I’ll move in with Mum!” Oliver shot back. “Fine,” Andrew said, unshaken. “But I’d hate for you to run when things get tough. And by the way, Mum’s in a cramped flat now. We’re buying a house—with a garden. Thought I’d set up a football goal.” Oliver, grumbling, gave in. “But don’t expect me to treat Lucy like a sister.” “Just respect,” Andrew said.
Lucy vowed the same—no friendship with Oliver. They married quietly, just family present. The kids sat through the meal with sour faces, radiating disdain.
A week later, they moved in. The teens’ rooms mirrored their clashing tastes. Lucy, an early bird, roamed the house at dawn while everyone slept. Oliver, a night owl, gamed till midnight and slept till noon on weekends. Lucy hated fish; Oliver could eat it daily. She loved K-pop and manga; he blasted punk rock and binge-watched action films. They had nothing in common. Every conversation devolved into bickering.
But Lucy unexpectedly warmed to Andrew. Her father had faded from her life, and Andrew, though strict, treated her like his own, even spoiling her more than Oliver. “She’s a girl,” he’d say. Oliver, meanwhile, bonded with Marina. His mother had always been distant, now too wrapped up in a new man to care. Marina listened without judgment, and soon Oliver confided in her.
Marina and Andrew hoped the kids would bond, but six months passed with no change. They came home separately, hung with different crowds at school, and hid in their rooms. The parents resigned themselves: as long as they weren’t at war.
Then everything shifted. Lucy had a persistent admirer—a boy from the year above. He gave her the creeps, messaging nonstop, leaving notes, asking her out. She said no outright, but he wouldn’t take the hint.
One night after drama club, Lucy lingered too long. As she left, the boy cornered her. “Come for a walk,” he said, blocking her path. “Leave me alone!” she snapped. “Don’t like me?” he scowled. “No! And you’re harassing me!” He grabbed her wrist. “You’re coming with me.” She struggled, but he was stronger.
Oliver, chatting with mates by the school gates, spotted them. Lucy looked terrified. Without thinking, he sprinted over, friends in tow. “Let her go!” he barked. “Who are you? Her boyfriend?” the guy sneered. “I’m her brother, idiot!” Oliver punched him square in the face. The boy fled under the glares of Oliver’s mates.
“He hurt you?” Oliver asked. “Just my wrist,” Lucy muttered, rubbing it. “Won’t leave me alone.” “He won’t bother you again,” one friend said. “You heading home?” Oliver asked. Lucy nodded, then whispered, “Thanks.”
For the first time, they walked home together. Marina, spotting them, held her breath, afraid to jin—
published: true
title: ‘[프로그래머스] Level 1 – 행렬의 덧셈’
layout: post
subtitle: ‘Programmers, Level 1’
categories: algorithm
tags: programmers problems
comments: true
use_math: true
—
# **문제**
> [`[프로그래머스] level 1 – 행렬의 덧셈`](https://school.programmers.co.kr/learn/courses/30/lessons/12950)
—
## **문제 설명 및 풀이**
numpy를 사용하면 금세 풀 수 있는 문제다. 다만, 프로그래머스에서는 numpy를 지원하지 않기에, 그냥 구현해주면 된다. 행렬의 덧셈은 주어진 두 리스트를 이중포문으로 돌며 더해주면 된다.
—
## **나의 코드**
“`python
import numpy as np
def solution(arr1, arr2):
nparr1 = np.array(arr1)
nparr2 = np.array(arr2)
answer = nparr1+nparr2
return answer.tolist()
“`
## **코드 without numpy**
“`python
def solution(arr1, arr2):
answer = []
for i in range(len(arr1)):
tmp = []
for j in range(len(arr1[0])):
tmp.append(arr1[i][j] + arr2[i][j])
answer.append(tmp)
return answer
“`
