From 94ba2da7b93c615910baa9031fe795878fbade95 Mon Sep 17 00:00:00 2001
From: Hidenobu Satsumi <stm323stm@gmail.com>
Date: Sun, 21 Feb 2021 22:10:08 +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 | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/app.js b/app.js
index ad9a93a7..4075ed5f 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,50 @@
 '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[3]);
+  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 rankingStrings = rankingArray.map(([key, value]) => {
+    return (
+      key +
+      ': ' +
+      value.popu10 +
+      '=>' +
+      value.popu15 +
+      ' 変化率:' +
+      value.change
+    );
+  });
+
+  console.log(rankingArray);
+});
\ No newline at end of file

From 41e03e0e0dc13944caced7f07fc0cd2fc6cea116 Mon Sep 17 00:00:00 2001
From: Hidenobu Satsumi <stm323stm@gmail.com>
Date: Mon, 22 Feb 2021 11:34:50 +0900
Subject: [PATCH 2/2] =?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 | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/app.js b/app.js
index 4075ed5f..52c64455 100644
--- a/app.js
+++ b/app.js
@@ -45,6 +45,5 @@ rl.on('close', () => {
       value.change
     );
   });
-
-  console.log(rankingArray);
+  console.log(rankingStrings);
 });
\ No newline at end of file