Create 149-max-points-on-a-line.js

Author: everthis

149-max-points-on-a-line.js

@@ -0,0 +1,26 @@
+/**
+ * @param {number[][]} points
+ * @return {number}
+ */
+const maxPoints = function (points) {
+  if (points.length < 2 || points == null) return points.length
+  let max = 2
+  for (let i = 0; i < points.length; i++) {
+    let [p1x, p1y] = points[i]
+    let samePoint = 1,
+      map = { base: 0 } // to avoid when map = {}, the max value is -Infinity
+    for (let j = i + 1; j < points.length; j++) {
+      if (points[i][0] == points[j][0] && points[i][1] == points[j][1]) {
+        samePoint++
+      } else {
+        let [p2x, p2y] = points[j]
+        let slope = (1000000.0 * (p2y - p1y)) / (p2x - p1x)
+        if (!Number.isFinite(slope)) slope = 'v'
+        else if (Number.isNaN(slope)) slope = 'h'
+        map[slope] = map[slope] + 1 || 1
+      }
+    }
+    max = Math.max(Math.max(...Object.values(map)) + samePoint, max)
+  }
+  return max
+}