daily

Author: Zanger67

my-submissions/m3025.md

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+Points sorted by $x$ then $-y$ since minimizing $x$ gives us the "leftmost" points and $-y$ gives us a secondary sorting based on the largest $y$ values. This lets us iterate and only check points right of a point in the list since any others are either left or above meaning the pairing has already been checked.
+
+Since the points are sorted in such a manner, when comparing two points the only points that could be "between" are those between the two in the points[] array since values that are between $x$-wise will be sorted between them first and $y$-wise as a secondary case.

my-submissions/m3025.py

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+class Solution:
+    def numberOfPairs(self, points: List[List[int]]) -> int:
+        points.sort(key=lambda x: (x[0], -x[1]))
+
+        output = 0
+        # Top left
+        for i, (x1, y1) in enumerate(points) :
+            # top right
+            for j, (x2, y2) in enumerate(points[i + 1:], i + 1) :
+                # valid pair
+                if x2 < x1 or y2 > y1 :
+                    continue
+                # Check for "between" points
+                if all(not (x1 <= x3 <= x2 and y2 <= y3 <= y1) for x3, y3 in points[i + 1:j]) :
+                    output += 1
+
+        return output