feat(2018 day-03): track claims to pieces of cloth

Author: developher-net

2018/day-03/claims.js

@@ -1,4 +1,55 @@
 var _conflicts = []
+var _claims = []
+
+/**
+ * Check if a value is within the designated range (inclusive)
+ * @param {number} s1 start of first range
+ * @param {number} e1 end of first range
+ * @param {number} s2 start of first range
+ * @param {number} e2 end of first range
+ */
+const _isOverlap = (s1, e1, s2, e2) => {
+  return Math.max(s1, e1) <= Math.min(s2, e2)
+}
+
+/**
+ * Compares claims to see if they overlap
+ * @param {Object} c1 claim to compare
+ * @param {Object*} c2 claim to compare
+ */
+const _isOverlappingClaim = (c1, c2) => {
+  // x range overlaps
+  const x = _isOverlap(
+    c1.x,
+    c1.x + c1.width,
+    c2.x,
+    c2.x + c2.width
+  )
+  // y range overlaps
+  const y = _isOverlap(
+    c1.y,
+    c1.y + c1.height,
+    c2.y,
+    c2.y + c2.height
+  )
+  return (x && y)
+}
+
+/**
+ * Iterates through the list of claims and checks to see if any cover the specified point
+ * @param {number} x point x value
+ * @param {number} y point y value
+ * @returns {Boolean}
+ */
+const isClaimed = (x, y) => {
+  const matches = _claims.filter((claim) =>
+    x >= claim.x &&
+    x <= claim.x + claim.width &&
+    y >= claim.y &&
+    y <= claim.y + claim.height
+  )
+  return (matches.length > 0)
+}
 
 /**
  * Logs a conflict about multiple claims for a singel point
@@ -17,6 +68,23 @@ const logConflict = (x, y, claims) => {
   }
 }
 
+const makeClaim = (claim) => {
+  // Check if there's any overlap with an exisiting claim
+  const overlaps = _claims.filter((existing) => _isOverlappingClaim(existing, claim))
+  if (overlaps.length > 0) {
+    console.log(`Claim ${claim.id} overlaps ${overlaps.length} already existing claims.`)
+    // step through individual points to log conflicts
+    for (let x = claim.x; x < claim.x + claim.width; x++) {
+      for (let y = claim.y; y < claim.y + claim.height; y++) {
+        if (isClaimed(x, y)) {
+          logConflict(x, y, [claim.id])
+        }
+      }
+    }
+  }
+  _claims.push(claim)
+}
+
 /**
  * Parses a claim into a usable object
  * @param {String} str formatted claim
@@ -43,6 +111,9 @@ const parseClaim = (str) => {
 
 module.exports = {
   _conflicts,
+  _claims,
+  isClaimed,
   logConflict,
+  makeClaim,
   parseClaim
 }

2018/day-03/claims.test.js

@@ -2,7 +2,7 @@
 const expect = require('chai').expect
 let {
   _conflicts,
-  cloth,
+  _claims,
   isClaimed,
   logConflict,
   makeClaim,
@@ -37,35 +37,29 @@ describe('--- Day 3: No Matter How You Slice It ---', () => {
   })
 
   describe('makeClaim(claim)', () => {
-    beforeEach(() => {
-      // Clear the stateful claims
-      cloth = {}
-    })
-
-    afterEach(() => {
-      // Clear the stateful claims
-      cloth = {}
-    })
-
     it('claims a piece of cloth for the specified elf', () => {
       const claim = parseClaim(claims[0])
       makeClaim(claim)
-      const expected = claim.id
-      for (let x = claim.x; x < claim.x + claim.width; x++) {
-        for (let y = claim.y; x < claim.y + claim.height; y++) {
-          expect(cloth[x][y]).to.equal(expected)
-        }
-      }
+      const actual = _claims.find((el) => el.x === claim.x && el.y === claim.y)
+      expect(actual).to.deep.equal(claim)
     })
 
-    it('does not claim points outside the region', () => {
-      const claim = parseClaim(claims[0])
-      makeClaim(claim)
-      expect(cloth.length).to.equal(claim.width)
-      cloth.forEach((col) => {
-        expect(col.length).to.equal(claim.height)
-      })
+    it('logs an overlap when one is encountered', () => {
+      const claim1 = claims[1]
+      const claim2 = claims[2]
+      makeClaim(claim1)
+      makeClaim(claim2)
+      expect(_conflicts)
     })
+
+    // it('does not claim points outside the region', () => {
+    //   const claim = parseClaim(claims[0])
+    //   makeClaim(claim)
+    //   expect(_cloth.length).to.equal(claim.width)
+    //   _cloth.forEach((col) => {
+    //     expect(col.length).to.equal(claim.height)
+    //   })
+    // })
   })
 
   describe('isClaimed(x,y)', () => {