From cd42ef2773f49b0a2d7eaff301d7d3bb4531f6eb Mon Sep 17 00:00:00 2001
From: StormtrooperR2 <84831296+StormtrooperR2@users.noreply.github.com>
Date: Fri, 28 May 2021 14:33:28 +0900
Subject: [PATCH] =?UTF-8?q?2010=20=E5=B9=B4=E3=81=8B=E3=82=89=202015=20?=
 =?UTF-8?q?=E5=B9=B4=E3=81=AB=E3=81=8B=E3=81=91=E3=81=A6=2015=E3=80=9C19?=
 =?UTF-8?q?=20=E6=AD=B3=E3=81=AE=E4=BA=BA=E3=81=8C=E6=B8=9B=E3=81=A3?=
 =?UTF-8?q?=E3=81=9F=E5=89=B2=E5=90=88=E3=81=AE=E9=83=BD=E9=81=93=E5=BA=9C?=
 =?UTF-8?q?=E7=9C=8C=E3=83=A9=E3=83=B3=E3=82=AD=E3=83=B3=E3=82=B0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 app.js | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/app.js b/app.js
index ad9a93a7..ecf9ef2a 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,51 @@
 '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 pair1[1].change - pair2[1].change;
+    });
+    const rankingString =rankingArray.map(([key, value],i) =>{
+        return ((i+1) + '位: '+key + ': ' + value.popu10 + '=>' + value.popu15 + ' 変化率: ' + value.change);
+    });
+
+    console.log(rankingString);
+});
+
+