Mar 3
Day 29 / 100 — Core tree patternsSolved on LeetCode:
• Maximum Depth of Binary Tree
• Invert Binary TreeHeight calculation.
Mirror transformation.“Master the basics.”#100DaysOfCode #BuildInPublic #LeetCode #Consistency
4
76
24 Dec 2025
<!doctype html>
<html lang="ja">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>目に悪い 七色デカツリー</title>
<style>
:root{
--bg:#07070b;
--glow: 18px;
}
html,body{height:100%; margin:0; background:var(--bg); overflow:hidden; font-family:system-ui, sans-serif;}
canvas{display:block; width:100vw; height:100vh;}
.hint{
position:fixed; left:12px; bottom:10px; color:#fff; opacity:.75;
font-size:12px; user-select:none; text-shadow:0 0 10px #000;
}
.hint kbd{background:rgba(255,255,255,.12); border:1px solid rgba(255,255,255,.25); padding:2px 6px; border-radius:6px;}
</style>
</head>
<body>
<canvas id="c"></canvas>
<div class="hint">
<kbd>Space</kbd>点滅ON/OFF / <kbd>↑↓</kbd>発光量 / <kbd>R</kbd>リセット
</div>
<script>
(() => {
const canvas = document.getElementById("c");
const ctx = canvas.getContext("2d", { alpha: false });
// 七色固定（はっきり7色）
const RAINBOW = [
"#ff2b2b", // 赤
"#ff8a1f", // 橙
"#ffe600", // 黄
"#00ff66", // 緑
"#00c8ff", // 水
"#2b58ff", // 青
"#b400ff" // 紫
];
let W=0,H=0, dpr=1;
function resize(){
dpr = Math.max(1, Math.min(2, window.devicePixelRatio || 1));
W = Math.floor(innerWidth * dpr);
H = Math.floor(innerHeight * dpr);
canvas.width = W; canvas.height = H;
}
addEventListener("resize", resize);
resize();
// 目に悪い制御
let strobe = true;
let glowBoost = 1.0;
addEventListener("keydown", (e) => {
if(e.code === "Space"){ strobe = !strobe; }
if(e.key === "ArrowUp"){ glowBoost = Math.min(2.5, glowBoost 0.1); }
if(e.key === "ArrowDown"){ glowBoost = Math.max(0.4, glowBoost - 0.1); }
if(e.key.toLowerCase() === "r"){ seed = (Math.random()*1e9)|0; buildOrnaments(); }
});
// 擬似乱数（安定配置用）
let seed = (Math.random()*1e9)|0;
function rnd(){
// xorshift32
seed ^= seed << 13; seed |= 0;
seed ^= seed >>> 17; seed |= 0;
seed ^= seed << 5; seed |= 0;
return ((seed >>> 0) / 4294967296);
}
// ツリー形パラメータ
function treeProfile(yNorm){
// yNorm: 0(頂点)〜1(裾)
// 幅が下ほど広がる（滑らかな円錐）
const t = Math.pow(yNorm, 0.9);
return 0.12 0.52 * t; // 横幅係数
}
// オーナメント（位置を“ツリー内部”にばらまく）
let ornaments = [];
function buildOrnaments(){
ornaments.length = 0;
const count = 220; // でかい
for(let i=0;i<count;i ){
const y = Math.pow(rnd(), 1.2); // 下に多め
const half = treeProfile(y);
const x = (rnd()*2 - 1) * half * (0.85 rnd()*0.25);
const r = (0.004 rnd()*0.012); // 半径（正規化）
ornaments.push({x, y, r, phase: rnd()*Math.PI*2, band: (i%7)});
}
// ライト（輪郭沿いに並べてツリー形を強調）
const outline = 220;
for(let i=0;i<outline;i ){
const y = i/(outline-1);
const half = treeProfile(y);
const side = (i%2===0)? -1 : 1;
const x = side * half * (0.92 0.05*Math.sin(i*0.2));
const r = 0.006 0.004*rnd();
ornaments.push({x, y, r, phase: rnd()*Math.PI*2, band: (i%7), outline:true});
}
}
buildOrnaments();
function drawStar(cx, cy, r, t){
const spikes = 5;
const outer = r;
const inner = r*0.45;
ctx.save();
ctx.translate(cx, cy);
ctx.rotate(t*0.6);
ctx.beginPath();
for(let i=0;i<spikes*2;i ){
const ang = (Math.PI*i)/spikes;
const rad = (i%2===0)? outer : inner;
ctx.lineTo(Math.cos(ang)*rad, Math.sin(ang)*rad);
}
ctx.closePath();
ctx.restore();
}
function glowCircle(x,y,r,color,alpha,blur){
ctx.save();
ctx.globalAlpha = alpha;
ctx.fillStyle = color;
ctx.shadowColor = color;
ctx.shadowBlur = blur;
ctx.beginPath();
ctx.arc(x,y,r,0,Math.PI*2);
ctx.fill();
ctx.restore();
}
function drawScanlines(time){
// スキャンライン（目に悪い）
ctx.save();
ctx.globalAlpha = 0.10;
ctx.fillStyle = "#000";
const step = Math.max(4, Math.floor(8*dpr));
for(let y=0; y<H; y =step){
const wobble = Math.floor((Math.sin(time*0.004 y*0.02) 1)*0.5*2);
ctx.fillRect(0, y wobble, W, Math.floor(step/2));
}
ctx.restore();
}
function frame(time){
// 背景フラッシュ（七色）
const bgIdx = Math.floor((time*0.004) % 7);
const bgPulse = strobe ? (0.18 0.22*Math.sin(time*0.02)) : 0.10;
ctx.fillStyle = "#07070b";
ctx.fillRect(0,0,W,H);
// 薄い虹フラッシュ
ctx.save();
ctx.globalAlpha = Math.max(0, bgPulse);
ctx.fillStyle = RAINBOW[bgIdx];
ctx.fillRect(0,0,W,H);
ctx.restore();
const cx = W*0.5;
const topY = H*0.12;
const baseY = H*0.88;
// ツリー本体（段々の円 = “葉”が見えるように）
const layers = 18;
for(let i=0;i<layers;i ){
const yNorm = i/(layers-1);
const y = topY (baseY-topY)*yNorm*0.92;
const half = treeProfile(yNorm);
const radius = (half * W*0.55) * (0.65 0.02*Math.sin(time*0.01 i));
const height = (H*0.02 yNorm*H*0.02);
// 葉っぱの色も虹に寄せる
const col = RAINBOW[(i Math.floor(time*0.01)) % 7];
ctx.save();
ctx.globalAlpha = 0.30;
ctx.fillStyle = col;
ctx.shadowColor = col;
ctx.shadowBlur = 14*glowBoost*dpr;
ctx.beginPath();
ctx.ellipse(cx, y, radius, height, 0, 0, Math.PI*2);
ctx.fill();
ctx.restore();
// 濃い中心
ctx.save();
ctx.globalAlpha = 0.18;
ctx.fillStyle = "#00ff66";
ctx.beginPath();
ctx.ellipse(cx, y, radius*0.72, height*0.75, 0, 0, Math.PI*2);
ctx.fill();
ctx.restore();
}
// 幹
const trunkW = W*0.07;
const trunkH = H*0.12;
ctx.save();
ctx.globalAlpha = 0.85;
ctx.fillStyle = "#5b2a12";
ctx.shadowColor = "#ffcc66";
ctx.shadowBlur = 10*glowBoost*dpr;
ctx.fillRect(cx - trunkW/2, baseY - trunkH*0.3, trunkW, trunkH);
ctx.restore();
// 星（頂点）
const starX = cx;
const starY = topY - H*0.02;
const starR = Math.min(W,H)*0.04;
// 星のグロー
const starColor = RAINBOW[Math.floor((time*0.02)%7)];
drawStar(starX, starY, starR, time*0.01);
ctx.save();
ctx.globalAlpha = strobe ? (0.75 0.25*Math.sin(time*0.05)) : 0.75;
ctx.fillStyle = "#fff7b0";
ctx.shadowColor = starColor;
ctx.shadowBlur = 45*glowBoost*dpr;
ctx.fill();
ctx.restore();
// オーナメント＆ライト（七色循環＋点滅）
const treeWidth = W*0.55;
const treeHeight = (baseY-topY)*0.92;
for(let i=0;i<ornaments.length;i ){
const o = ornaments[i];
const x = cx o.x*treeWidth;
const y = topY o.y*treeHeight;
// 7色を“明確に”切り替えつつ、少し時間でずらす
const idx = (o.band Math.floor((time*0.03 o.phase)*1.2)) % 7;
const col = RAINBOW[idx];
const blink = strobe ? (0.55 0.45*Math.sin(time*0.06 o.phase*3)) : 0.9;
const baseR = o.r*Math.min(W,H);
// 輪郭ライトはより強く
const intensity = o.outline ? 1.25 : 1.0;
const blur = (o.outline ? 42 : 28) * glowBoost * dpr;
// 外側グロー
glowCircle(x,y, baseR*1.35, col, 0.45*blink*intensity, blur);
// 本体
glowCircle(x,y, baseR*0.85, "#ffffff", 0.20*blink*intensity, 10*glowBoost*dpr);
glowCircle(x,y, baseR*0.70, col, 0.95*blink*intensity, 18*glowBoost*dpr);
// ちょいハイライト
ctx.save();
ctx.globalAlpha = 0.35*blink;
ctx.fillStyle = "#fff";
ctx.beginPath();
ctx.arc(x-baseR*0.25, y-baseR*0.25, baseR*0.22, 0, Math.PI*2);
ctx.fill();
ctx.restore();
}
// スノー（視界にノイズを足す）
const flakes = 260;
ctx.save();
ctx.globalAlpha = 0.28;
for(let i=0;i<flakes;i ){
const fx = ( (i*997 time*0.12) % W );
const fy = ( (i*571 time*0.55) % H );
const size = ( (i%7) 1 ) * 0.35 * dpr;
ctx.fillStyle = RAINBOW[(i Math.floor(time*0.01)) % 7];
ctx.fillRect(fx, fy, size, size);
}
ctx.restore();
// スキャンライン
drawScanlines(time);
requestAnimationFrame(frame);
}
requestAnimationFrame(frame);
})();
</script>
</body>
</html>
2
3
720
1 Jul 2025
✅ Day 81 of #gfg160 #geekstreak2025
Problem: Height of Binary Tree
🌿 Used simple recursion: height = 1 max(left, right)
🧠 Base case for null node ensures depth accuracy
@geeksforgeeks #cpp #dsa #binarytree #recursion #treeheight #100daysofcode #gfg160 #codingchallenge
2
21
30 Jun 2025
【EDITOR'S CHOICE】
#Parameterization of height–diameter and crown radius–diameter relationships across the globe
#TreeHeight | #DiameteratBreastHeight | #CrownRadius | #FittingFunction | #VegetationModel
doi.org/10.1093/jpe/rtae005
2
58
8 Jun 2025
In the forest 🌳 measuring tree height and canopy cover using a clinometer.
Fieldwork like this connects theory to practice — and nature always has something to teach. 🌲📐 #Forestry #Fieldwork #TreeHeight #AgriScience #SustainableForests
3
7
16
333
5 Jun 2025
Thank you for the shout-out! 🙌
Here's my step-by-step video walkthrough: youtu.be/EECMHPn2Iuc
📘 Want a full, project-by-project roadmap—from your first coordinate to publication-ready cartography?
Mapping Worlds with R: Your Journey from Beginner to Data Cartographer → payhip.com/b/MH9Ot
#RStats #RayShader #TreeHeight #DataVisualization #OpenData #Geospatial
12
81
7,466
7 Feb 2025
🌟 Day 81 of #gfg160
Today's challenge with @geeksforgeeks : "Find the Height of a Binary Tree."
Determining the longest path from root to leaf in the tree! 🌲📏✨
#geekstreak2024 #BinaryTrees #TreeHeight #DSA #TreeTraversal
2
19
3 Feb 2025
Day 81 of #geekstreak2024
Height of Binary Tree
🔹 Uses BFS (Level Order Traversal)
🔹 Counts number of levels in the tree
🔹 Returns depth - 1 to count edges instead of nodes
#gfg160 #BinaryTree #TreeHeight #DSA
13
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7 Nov 2024
Check this out from our friends at @SciStarter! SciStarter's own, Bob Hirshon, measures the #TreeHeight and tree circumference of a California Redwood with the GLOBE Observer Trees Tool! How many tree heights have you measured? Keep those observations coming. We need that data!
7 Nov 2024
🌲 Join Bob Hirshon from SciStarter as he explores the majestic Redwoods with the @GLOBEProgram: Trees Observer tool!
With just a few steps on the GLOBE Observer app, you too can help track forest health and contribute to NASA’s vital research on carbon storage and climate impact.
Start today and help monitor our planet’s #carbon balance! scistarter.org/globe-observe…
1
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328
22 Oct 2024
Today is #SmartIsCoolDay! GLOBE would love to thank all our GLOBE observers for being both smart and cool and for taking #Cloud, #MosquitoHabitat, #LandCover, and #TreeHeight observations, providing student and professional researchers with important environmental data. Want to get involved? Do GLOBE: globe.gov/do-globe!
ALT There are three images of people taking observations outdoors.
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160
9 Sep 2024
✨Highlights cont'd✨
Results showed that the change in forest structure driven by spruce budworm in Quebec is driven by #CanopyCover and #TreeHeight and that initial forest structures can modulate infestation severity
3
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🔓 OPEN ACCESS article:
Ticehurst & Newnham (@CSIRO) generate Australia-wide, time-series annual #vegetation height layers from 1988 to 2022, using #GEDI #LiDAR data and #Landsat imagery.
🔗 doi.org/10.1080/01431161.202…
#IJRS #RemoteSensing #ForestMapping #TreeHeight
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4
241
27 Aug 2024
Did you know that today, Tuesday, 27 August 2024 is #JustBecauseDay? Today would be a great day to take GLOBE Observer #Clouds, #MosquitoHabitat, #LandCover, and #TreeHeight observations. Why? Just because! Plus, all your data is vital
to GLOBE and researchers!
3
147
15 Aug 2024
Did you know that today, 15 August, is #NationalRelaxationDay? While you are relaxing, how about taking a few GLOBE Observer #clouds, #MosquitoHabitatMapper, #LandCover, and #TreeHeight observations? We always look forward to your observations. observer.globe.gov/.
ALT Screen shot of the GLOBE Program's GLOBE Observer App.
3
7
172
19 Jun 2024
🌲🌲🌲JFR New Free Paper on #ForestModel
Ecoregional height–diameter models for Scots pine in #Turkiye #TreeHeight #NonlinearModelling
#Ecoregion #ScotsPine
doi.org/10.1007/s11676-024-0…
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155
18 May 2024
🏙️🌳 Is #Brazil's 🇧🇷 #UrbanForest as green as it seems?🤔A study reveals #inequality in #CanopyCover & I'm diving deep into tree heights to see if the greenest cities have the tallest trees!#TreeHeight #BrazilCities #UrbanPlanning #Sustainability #Environment #DeepLearning #ISPRS
6 Nov 2023
How are people in Brazil exposed to the #UrbanTreeCanopy? What role do #climatic factors play in determining #UTC occultation patterns?
Jianhua made a systematic analysis with 472 brazil cities with UTC derived from #AI4EO
Link to paper @SustainableCit8: sciencedirect.com/science/ar…
1
3
1,362
22 Jan 2024
Winter is in full swing in the Northern Hemisphere! Have you seen snow this winter? Have you taken GLOBE Observer #LandCover or #TreeHeight observations in a snowy environment? Check out these snowy land cover and tree height observation photos taken in the chilly outdoors.
ALT Global map with seven snow images from around the world. The images are from United States, Canada, Poland, Sweden, Ukraine, and Mongolia.
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3
219
16 Jan 2024
The @NASA ICESat and ICESat-2 satellites have taken billions of vital Earth #TreeHeight observations from space. These space-based tree height data can be used as comparison data to our awesome GLOBE Observer volunteers' ground-based tree height data taken using the Trees Tool.
12 Jan 2024
The first ICESat mission launched on this day in 2003. How did we develop the technology to study the changing height of Earth's ice from space? Follow the journey with our Leaders in Lidar series: plus.nasa.gov/series/leaders…
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9 Jan 2024
Check out the latest @SciStarter episode, “Monitoring and Protecting Trees,” as part of the “Science We Can Do Together series.” GLOBE Observer Trees is one of the features in the video. Visit bit.ly/3vpma7h to see how you can help @NASA and GLOBE measure #TreeHeight.
ALT SciStarter Image of a forest, looking up from below at tree canopy.
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179
28 Dec 2023
Today, 28 Dec 2023 is #NationalDownloadDay! If you haven’t already, today would be the perfect day to download the GLOBE Observer App and get started taking #Cloud, #MosquitoHabitatMapper, #LandCover, and #TreeHeight observations. Learn more at observer.globe.gov.
ALT Image of two hands holding up a cell phone with the GLOBE Observer App Clouds Tool on screen. The background contains clouds, trees and mountainous rock.
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