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149-max-points-on-a-line/149-max-points-on-a-line.py

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+class Solution:
+    def maxPoints(self, points: List[List[int]]) -> int:
+        # A unique line can be created by choosing two points
+        # A line can be represented using two numbers m,b (mx+b)
+        
+        # Base cases: 1 or 2 points in the array
+        if len(points) <= 2:
+            return len(points)
+        
+        # Key = "m,b" (for horizontal or oblique lines) or "vX" (for vertical lines)
+        # Value = array of x-values (y-values for vertical lines)
+        lines = {}
+        
+        for i in range(len(points)):
+            for j in range(i + 1, len(points)):
+                # p1 is the first value on the x-axis
+                p1, p2 = (points[i], points[j]) if (points[i][0] < points[j][0]) else (points[j], points[i])
+                
+                # Vertical lines
+                if p1[0] == p2[0]:
+                    vX = f"v{p1[0]}"
+                    if vX in lines:
+                        if p1[1] not in lines[vX]:
+                            lines[vX].append(p1[1])
+                        if p2[1] not in lines[f"v{p1[0]}"]:
+                            lines[vX].append(p2[1])
+                    else:
+                        lines[vX] = [p1[1], p2[1]]
+                    continue
+                    
+                # Horizontal and Obliques lines
+                m = (p2[1] - p1[1]) / (p2[0] - p1[0])
+                b = p1[1] - (p1[0] * m)
+                mb = f"{m},{b}"
+                
+                if mb in lines:
+                    if p1[0] not in lines[mb]:
+                        lines[mb].append(p1[0])
+                    if p2[0] not in lines[mb]:
+                        lines[mb].append(p2[0])
+                else:
+                    lines[mb] = [p1[0], p2[0]]
+              
+        # Find max len(x-vals) in lines **Can be optimized (put into above)**
+        maxPoints = 0
+        for lSym in lines.keys():
+            if maxPoints < len(lines[lSym]):
+                maxPoints = len(lines[lSym])
+           
+        return maxPoints