some sec fixes

FibonacciWindow.xaml.cs

@@ -35,7 +35,7 @@ namespace Lab
             long a = 1;
             long b = 1;
             List<long> list = new List<long>();
-            while (a < n) { list.Add(a); long next = a + b; a = b; b = next; }
+            while (a < n) { list.Add(a); if (long.MaxValue - a < b) break; long next = a + b; a = b; b = next; }
 
             OutBox.Text = string.Join(", ", list);
             InfoText.Text = $"Найдено чисел: {list.Count}.";

Matrices.cs

@@ -79,7 +79,9 @@ namespace Lab
             {
                 for (int col = 0; col < cols; col++)
                 {
-                    array[row, col] = Convert.ToInt32(dt.Rows[row][col]);
+                    double num = (double)dt.Rows[row][col];
+                    num = double.IsInfinity(num) || double.IsNaN(num) ? 0 : num;
+                    array[row, col] = Convert.ToInt32(num);
                 }
             }
 

MatrixFlipWindow.xaml.cs

@@ -41,6 +41,12 @@ namespace Lab
                 return false;
             }
 
+            if (rows > 50 || cols > 50)
+            {
+                FlipInfoText.Text = "Возможно, но превосходит вычислительные мощности.";
+                return false;
+            }
+
             return true;
         }
 

Parsers.cs

@@ -3,12 +3,13 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Globalization;
 
 namespace Lab
 {
     internal class Parsers
     {
-        public static bool TryParseDouble(string? s, out double val) => double.TryParse((s ?? "").Trim().Replace(",", "."), out val);
+        public static bool TryParseDouble(string? s, out double val) => double.TryParse((s ?? "").Trim().Replace(",", "."), NumberStyles.Float, CultureInfo.InvariantCulture, out val) && !double.IsNaN(val) && !double.IsInfinity(val);
         public static bool TryParseInt(string? s, out int val) => int.TryParse((s ?? "").Trim(), out val);
         
         public static bool TryParseDoubleArray(string? s, out double[] vals, out string err)
@@ -21,7 +22,7 @@ namespace Lab
                 return false;
             }
 
-            string[] parts = s.Split(new[] { ' ', '\t', '\n', '\r', ',', ';' });
+            string[] parts = s.Split(new[] { ' ', '\t', '\n', '\r', ',', ';' }, StringSplitOptions.RemoveEmptyEntries);
 
             List<double> list = new List<double>();