add leetcode 149

Author: betomoedano

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

@@ -0,0 +1,37 @@
+/**
+ * @param {number[][]} points
+ * @return {number}
+ * Time O(n^2)
+ * Space O(n)
+ */
+
+function maxPoints(points) {
+  if (points.length <= 2) return points.length;
+
+  let maxCount = 0;
+  for (let i = 0; i < points.length; i++) {
+    let slopeCount = {};
+    let samePoints = 1;
+    for (let j = 0; j < points.length; j++) {
+      if (i === j) continue;
+      if (points[i][0] === points[j][0] && points[i][1] === points[j][1]) {
+        samePoints++;
+        continue;
+      }
+      let slope = (points[i][1] - points[j][1]) / (points[i][0] - points[j][0]);
+      if (slope in slopeCount) {
+        slopeCount[slope]++;
+      } else {
+        slopeCount[slope] = 1;
+      }
+    }
+    console.log(slopeCount);
+    let count = samePoints;
+    for (let slope in slopeCount) {
+      count = Math.max(count, slopeCount[slope] + samePoints);
+    }
+    maxCount = Math.max(maxCount, count);
+  }
+
+  return maxCount;
+}