はじめに

少し前から自己研鑽のためにLeetCodeという競技プログラミングの問題を解いています。
paiza×Qiita記事投稿キャンペーンを機にpaizaの問題を解いていこうと思い、コードを公開します。

前回はDランクの問題だったので、今回はCランクの問題です。
言語はJavaScript（TypeScriptがなかった...）を選択しています。

Dランクはこちら

宝くじ

process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
  const isAdjacent = (winNumber, num) => {
    if ((winNumber !== 100000) && (num === winNumber-1)) {
      return true;
    } else if ((winNumber !== 199999) && (num === winNumber+1)) {
      return true;
    } else {
      return false;
    }
  };
  
  const isSecond = (winNumber, num) => {
    return (winNumber % 10000) === (num % 10000);
  };
  
  const isThird = (winNumber, num) => {
      return (winNumber % 1000) === (num % 1000);
  };
  
  const winNumber = Number(lines[0]);
  
  for(let i=2; i<Number(lines[1])+2; i++){
      const num = Number(lines[i]);
      
      if (num === winNumber) {
          console.log('first');
      } else if (isAdjacent(winNumber, num)) {
          console.log('adjacent');
      } else if (isSecond(winNumber, num)) {
          console.log('second');
      } else if (isThird(winNumber, num)) {
          console.log('third');
      } else {
          console.log('blank');
      }
  }
});

野球の審判

process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
  let strkes = 0;
  let balls = 0;
  for (let i=1; i<Number(lines[0])+1; i++) {
      const judge = lines[i];
      if (judge === 'strike') {
          if (strkes === 2) {
            console.log('out!');
          } else {
            console.log('strike!');
            strkes++;
          }
      } else {
          if (balls === 3) {
            console.log('fourball!');
          } else {
            console.log('ball!');
            balls++;
          }
      }
  }
});

みかんの仕分け

process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
  const NM = lines[0].split(' ');
  const N = Number(NM[0]);
  const M = Number(NM[1]);
  
  for (let m=1; m<M+1; m++) {
    const w = lines[m];
    const addIndex = ((N / 2) <= (w % N)) ? 1 : 0;
    const index = Math.floor(w / N);
    
    let box;
    if (index === 0) {
      box = N;
    } else {
      box = (index + addIndex) * N;
    }
    console.log(box);
  }
});

Fizz Buzz

process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
  for (let i=1; i<=Number(lines[0]); i++) {
    if ((i % 15) === 0) {
      console.log('Fizz Buzz');
    } else if ((i % 3) === 0) {
      console.log('Fizz');
    } else if ((i % 5) === 0) {
      console.log('Buzz');
    } else {
      console.log(i);
    }
  }
});

残り物の量

process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = [];
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});
reader.on('line', (line) => {
  lines.push(line);
});
reader.on('close', () => {
  const mpq = lines[0].split(' ');
  const m = Number(mpq[0]);
  const p = Number(mpq[1]);
  const q = Number(mpq[2]);
  
  const freshed = m * p / 100;
  const dished = (m - freshed) * q / 100;
  
  console.log(m - freshed - dished);
});

さいごに

Cランクもそこまで複雑な問題はない印象です。
Dランクの次ステップとしていい感じの難易度かなと感じました。