From aa6791969030beb0f904375977dccc3c4d8c9608 Mon Sep 17 00:00:00 2001
From: Yuzuko Niigaki <yozukon@array.co.jp>
Date: Wed, 3 Mar 2021 15:31:41 +0900
Subject: [PATCH 1/2] =?UTF-8?q?=E3=83=A9=E3=83=B3=E3=82=AD=E3=83=B3?=
 =?UTF-8?q?=E3=82=B0=E3=81=AE=E5=AE=9F=E8=A3=85=E5=AE=8C=E4=BA=86?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 app.js | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/app.js b/app.js
index ad9a93a7..577d0300 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,49 @@
 'use strict';
+const fs = require('fs');
+const readline = require('readline');
+const rs = fs.createReadStream('./popu-pref.csv');
+const rl = readline.createInterface({ input: rs, output: {} });
+const prefectureDataMap = new Map(); // key: 都道府県 value: 集計データのオブジェクト
+rl.on('line', lineString => {
+    const columns = lineString.split(',');
+    const year = parseInt(columns[0]);
+    const prefecture = columns[1];
+    const popu = parseInt(columns[2]);
+    if (year === 2010 || year === 2015) {
+        let value = prefectureDataMap.get(prefecture);
+        if (!value) {
+            value = {
+                popu10: 0,
+                popu15: 0,
+                change: null
+            }
+        }
+        if (year === 2010) {
+            value.popu10 = popu;
+        }
+        if (year === 2015) {
+            value.popu15 = popu;
+        }
+        prefectureDataMap.set(prefecture, value);
+    }
+})
+rl.on('close', () => {
+    for (let [key, value] of prefectureDataMap) {
+        value.change = value.popu15 / value.popu10;
+    }
+    const rankingArray = Array.from(prefectureDataMap).sort((pair1, pair2) => {
+        return pair2[1].change - pair1[1].change;
+    })
+    const rankingString = rankingArray.map(([key, value]) => {
+        return (
+            key +
+            ': ' +
+            value.popu10 +
+            '=>' +
+            value.popu15 +
+            ' 変化率' +
+            value.change
+        );
+    })
+    console.log(rankingString);
+})
\ No newline at end of file

From 0740a4fe82d64c96a91d09e8f4214768446626c3 Mon Sep 17 00:00:00 2001
From: Yuzuko Niigaki <yozukon@array.co.jp>
Date: Wed, 3 Mar 2021 15:40:12 +0900
Subject: [PATCH 2/2] =?UTF-8?q?=E6=B8=9B=E5=B0=91=E3=83=A9=E3=83=B3?=
 =?UTF-8?q?=E3=82=AD=E3=83=B3=E3=82=B0=E3=81=AB=E6=94=B9=E5=A4=89=E3=80=81?=
 =?UTF-8?q?=E9=A0=86=E4=BD=8D=E3=81=AE=E5=87=BA=E5=8A=9B=E8=BF=BD=E5=8A=A0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 app.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/app.js b/app.js
index 577d0300..5bbe66f1 100644
--- a/app.js
+++ b/app.js
@@ -32,10 +32,12 @@ rl.on('close', () => {
         value.change = value.popu15 / value.popu10;
     }
     const rankingArray = Array.from(prefectureDataMap).sort((pair1, pair2) => {
-        return pair2[1].change - pair1[1].change;
+        return pair1[1].change - pair2[1].change;
     })
-    const rankingString = rankingArray.map(([key, value]) => {
+    const rankingString = rankingArray.map(([key, value], i) => {
         return (
+            (i + 1) +
+            '位 ' +
             key +
             ': ' +
             value.popu10 +