Create 3027.js

Author: Chiki1601

3001-3500/3027.js

@@ -0,0 +1,26 @@
+function numberOfPairs(points) {
+    // Step 1: Sort points by x ascending, then by y descending
+    points.sort((a, b) => {
+        if (a[0] === b[0]) return b[1] - a[1];
+        return a[0] - b[0];
+    });
+    let pairCount = 0;
+    const n = points.length;
+
+    // Step 2: Iterate through all points as potential "upper-left" points
+    for (let i = 0; i < n; i++) {
+        const upperY = points[i][1];
+        let lowerYLimit = Number.MIN_SAFE_INTEGER;
+
+        // Step 3: Check subsequent points as potential "bottom-right" points
+        for (let j = i + 1; j < n; j++) {
+            const currentY = points[j][1];
+            if (currentY <= upperY && currentY > lowerYLimit) {
+                pairCount++;
+                lowerYLimit = currentY;
+                if (currentY === upperY) break;
+            }
+        }
+    }
+    return pairCount;
+}