From 1503a33bb0a551084213ba50ed2b79297decae1f Mon Sep 17 00:00:00 2001
From: ShokiYokota <syoki.yokota@azone-japan.co.jp>
Date: Tue, 17 Oct 2023 22:47:52 +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 | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/app.js b/app.js
index ad9a93a..43d8816 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,45 @@
-'use strict';
+'use strict'
+const fs = require('node:fs')
+const readline = require('node:readline')
+const rs = fs.createReadStream('./popu-pref.csv')
+const rl = readline.createInterface({ input: rs })
+// key: 都道府県 value: 集計データのオブジェクト
+const prefectureDataMap = new Map()
+
+rl.on('line', (lineString) => {
+  const columns = lineString.split(',')
+  const year = parseInt(columns[0])
+  const prefecture = columns[1]
+  const population = parseInt(columns[3])
+  if (year === 2016 || year === 2021) {
+    let value = null
+    if (prefectureDataMap.has(prefecture)) {
+      value = prefectureDataMap.get(prefecture)
+    } else {
+      value = {
+        before: 0,
+        after: 0,
+        change: null,
+      }
+    }
+    if (year === 2016) {
+      value.before = population
+    }
+    if (year === 2021) {
+      value.after = population
+    }
+    prefectureDataMap.set(prefecture, value)
+  }
+})
+rl.on('close', () => {
+  for (const [key, value] of prefectureDataMap) {
+    value.change = value.after / value.before
+  }
+  const rankingArray = Array.from(prefectureDataMap).sort((pair1, pair2) => {
+    return pair2[1].change - pair1[1].change
+  })
+  const rankigStrings = rankingArray.map(([key, value]) => {
+    return `${key}: ${value.before} => ${value.after} 変化率：${value.change}`
+  })
+  console.log(rankigStrings)
+})

From dd60939e08fb65ad0f12b8502d62399a9c29acfb Mon Sep 17 00:00:00 2001
From: ShokiYokota <syoki.yokota@azone-japan.co.jp>
Date: Tue, 17 Oct 2023 23:11:45 +0900
Subject: [PATCH 2/2] =?UTF-8?q?=E6=B8=9B=E3=81=A3=E3=81=9F=E5=89=B2?=
 =?UTF-8?q?=E5=90=88=E3=83=A9=E3=83=B3=E3=82=AD=E3=83=B3=E3=82=B0=E3=81=AB?=
 =?UTF-8?q?=E5=A4=89=E6=9B=B4?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 app.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/app.js b/app.js
index 43d8816..7ddb695 100644
--- a/app.js
+++ b/app.js
@@ -36,10 +36,12 @@ rl.on('close', () => {
     value.change = value.after / value.before
   }
   const rankingArray = Array.from(prefectureDataMap).sort((pair1, pair2) => {
-    return pair2[1].change - pair1[1].change
+    return pair1[1].change - pair2[1].change
   })
-  const rankigStrings = rankingArray.map(([key, value]) => {
-    return `${key}: ${value.before} => ${value.after} 変化率：${value.change}`
+  const rankigStrings = rankingArray.map(([key, value], index) => {
+    return `${index + 1}位 ${key}: ${value.before} => ${value.after} 変化率：${
+      value.change
+    }`
   })
   console.log(rankigStrings)
 })