add new solutions

solutions/30/q3047/solution.go

@@ -0,0 +1,42 @@
+package q3047
+
+import "slices"
+
+func intersectingSquareArea(bl1, tr1, bl2, tr2 []int) int64 {
+	l1, r1, l2, r2 := bl1[0], tr1[0], bl2[0], tr2[0]
+	iW := max(0, min(r1, r2)-max(l1, l2))
+
+	l1, r1, l2, r2 = bl1[1], tr1[1], bl2[1], tr2[1]
+	iH := max(0, min(r1, r2)-max(l1, l2))
+
+	edge := min(iW, iH)
+	return int64(edge * edge)
+}
+
+func largestSquareArea(bottomLeft [][]int, topRight [][]int) int64 {
+	squares := make([]int, len(bottomLeft))
+	for i := range squares {
+		squares[i] = i
+	}
+	slices.SortFunc(squares, // bottom-up order
+		func(a, b int) int { return bottomLeft[a][1] - bottomLeft[b][1] })
+
+	var largest int64
+
+	for i := range squares {
+		for j := i + 1; j < len(squares); j++ {
+			yI, yJ := topRight[squares[i]][1], bottomLeft[squares[j]][1]
+			if yJ >= yI {
+				break
+			}
+
+			largest = max(largest, intersectingSquareArea(
+				bottomLeft[squares[i]], topRight[squares[i]],
+				bottomLeft[squares[j]], topRight[squares[j]],
+			))
+		}
+	}
+	return largest
+}
+
+var _ = largestSquareArea