add new solutions

solutions/0/q85/solution.go

@@ -0,0 +1,31 @@
+package q85
+
+func maximalRectangle(matrix [][]byte) int {
+	var maxArea int
+
+	for row := range matrix {
+		for col := range matrix[0] {
+			matrix[row][col] -= '0'
+			if matrix[row][col] == 0 {
+				continue
+			}
+
+			if col > 0 {
+				matrix[row][col] += matrix[row][col-1]
+			}
+
+			maxW := matrix[row][col]
+			for i := 0; row-i >= 0; i++ {
+				if matrix[row-i][col] == 0 {
+					break
+				}
+				maxW = min(maxW, matrix[row-i][col])
+				maxArea = max(maxArea, int(maxW)*(i+1))
+			}
+		}
+	}
+
+	return maxArea
+}
+
+var _ = maximalRectangle