couple more days of 2019

2019/03/part1.js

@@ -0,0 +1,39 @@
+const fs = require('fs');
+const text = fs.readFileSync("./2019/03/input.txt", "utf-8");
+
+let lineIns = text.split('\n').map(line => line.split(','))
+let linePoints = [];
+
+for (let line = 0; line < 2; line++){
+	let points = [[0,0]];
+	for (let i = 0; i < lineIns[line].length; i++){
+		let segment = lineIns[line][i];
+		let dist = parseInt(segment.slice(1));
+		let axis = ((segment[0] == "R") || (segment[0] == "L")) ? 0 : 1;
+		let dir = ((segment[0] == "R") || (segment[0] == "U")) ? 1 : -1;
+		let coord = points[i];
+		coord[axis] += dir * dist;
+		coord.axis = axis;
+		points.push(coord.slice());
+	}
+	linePoints.push(points);
+}
+
+let closest = Infinity;
+for (let i = 0; i < linePoints[0].length-1; i++) {
+	let segment0 = linePoints[0].slice(i, i+2);
+	let axis0 = linePoints[0][i].axis;
+	segment0.sort((a, b) => a[(axis0+1)%2] - b[(axis0+1)%2]);
+	for (let j = 0; j < linePoints[1].length-1; j++) {
+		let axis1 = linePoints[1][j].axis;
+		if (axis0 == axis1) continue;
+		let segment1 = linePoints[1].slice(j, j+2);
+		segment1.sort((a, b) => a[(axis1+1)%2] - b[(axis1+1)%2]);
+		if (segment0[0][axis0] >= segment1[0][axis0] && segment0[1][axis0] <= segment1[1][axis0] &&
+			segment1[0][axis1] >= segment0[0][axis1] && segment1[1][axis1] <= segment0[1][axis1]) {
+			let cross = Math.abs(segment0[0][axis0]) + Math.abs(segment1[0][axis1]);
+			closest = closest < cross ? closest : cross;
+		}
+	}
+}
+console.log(closest);