adding algo

src/my_project/interviews/top_150_questions_round_22/ex_131_max_points_in_a_line.py

@@ -0,0 +1,26 @@
+from math import gcd
+from typing import List
+
+
+class Solution:
+    def maxPoints(self, points: List[List[int]]) -> int:
+        n = len(points)
+        if n <= 2:
+            return n
+        result = 2
+        for i in range(n):
+            slopes = {}
+            for j in range(i + 1, n):
+                dx = points[j][0] - points[i][0]
+                dy = points[j][1] - points[i][1]
+                g = gcd(dx, dy)
+                dx //= g
+                dy //= g
+                if dx < 0:
+                    dx, dy = -dx, -dy
+                elif dx == 0:
+                    dy = abs(dy)
+                slopes[(dx, dy)] = slopes.get((dx, dy), 0) + 1
+            if slopes:
+                result = max(result, max(slopes.values()) + 1)
+        return result

src/my_project/interviews_typescript/top_150_questions_round_1/ex_131_max_points_in_a_line.ts

@@ -0,0 +1,39 @@
+function maxPoints(points: number[][]): number {
+    const n = points.length;
+    if (n <= 2) return n;
+    let result = 2;
+    for (let i = 0; i < n; i++) {
+        const slopes = new Map<string, number>();
+        for (let j = i + 1; j < n; j++) {
+            let dx = points[j][0] - points[i][0];
+            let dy = points[j][1] - points[i][1];
+            const g = gcd(Math.abs(dx), Math.abs(dy));
+            dx /= g;
+            dy /= g;
+            if (dx < 0) {
+                dx = -dx;
+                dy = -dy;
+            } else if (dx === 0) {
+                dy = Math.abs(dy);
+            }
+            const key = `${dx},${dy}`;
+            slopes.set(key, (slopes.get(key) || 0) + 1);
+        }
+        if (slopes.size > 0) {
+            for (const count of slopes.values()) {
+                result = Math.max(result, count + 1);
+            }
+        }
+    }
+    return result;
+}
+
+function gcd(a: number, b: number): number {
+    while (b !== 0) {
+        [a, b] = [b, a % b];
+    }
+    return a;
+}
+
+console.log(maxPoints([[1, 1], [2, 2], [3, 3]]));
+console.log(maxPoints([[1, 1], [3, 2], [5, 3], [4, 1], [2, 3], [1, 4]]));

tests/test_150_questions_round_22/test_131_max_points_in_a_lines_round_22.py

@@ -0,0 +1,29 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_131_max_points_in_a_line import Solution
+
+class MaxPointsInALineTestCase(unittest.TestCase):
+
+    def setUp(self):
+        self.solution = Solution()
+
+    def test_three_collinear_points(self):
+        self.assertEqual(3, self.solution.maxPoints([[1, 1], [2, 2], [3, 3]]))
+
+    def test_six_points(self):
+        self.assertEqual(4, self.solution.maxPoints(
+            [[1, 1], [3, 2], [5, 3], [4, 1], [2, 3], [1, 4]]))
+
+    def test_single_point(self):
+        self.assertEqual(1, self.solution.maxPoints([[0, 0]]))
+
+    def test_two_points(self):
+        self.assertEqual(2, self.solution.maxPoints([[0, 0], [1, 1]]))
+
+    def test_vertical_line(self):
+        self.assertEqual(3, self.solution.maxPoints([[1, 1], [1, 2], [1, 3]]))
+
+    def test_horizontal_line(self):
+        self.assertEqual(3, self.solution.maxPoints([[1, 1], [2, 1], [3, 1]]))
+
+