Step by Step solution about How to resolve the algorithm Integer overflow step by step in the C# programming language

Explanation:

The provided code demonstrates integer overflow in C# for different integer data types. Integer overflow occurs when the result of a mathematical operation exceeds the maximum or minimum value that can be represented by the data type.

Unchecked Block:

unchecked is a C# keyword that suppresses overflow checking for the code within its block. This means that any integer overflow will not cause an OverflowException to be thrown.

For 32-bit Signed Integers:

• -(-2147483647 - 1): Negating the minimum integer value results in the maximum integer value (2147483647).
• 2000000000 + 2000000000: Adding two large positive numbers overflows and results in a negative value (-147483648).
• -2147483647 - 2147483647: Subtracting the minimum integer value from itself overflows and results in 0.
• 46341 * 46341: Multiplying two large numbers overflows and results in a negative value (-1073741824).
• ((-2147483647 - 1) / -1): Dividing the minimum integer value by -1 overflows and results in the maximum integer value (2147483647).

For 64-bit Signed Integers:

• -(-9223372036854775807L - 1): Negating the minimum 64-bit integer value results in the maximum integer value (9223372036854775807).
• 5000000000000000000L + 5000000000000000000L: Adding two large positive numbers overflows and results in a negative value (-5000000000000000000).
• -9223372036854775807L - 9223372036854775807L: Subtracting the minimum 64-bit integer value from itself overflows and results in 0.
• 3037000500L * 3037000500L: Multiplying two large numbers overflows and results in a negative value (-3689348814741910324).
• ((-9223372036854775807L - 1) / -1): Dividing the minimum 64-bit integer value by -1 overflows and results in the maximum integer value (9223372036854775807).

For 32-bit Unsigned Integers:

• -4294967295U: Negating a 32-bit unsigned integer converts it to a 64-bit signed integer, resulting in the minimum 64-bit signed integer value (-9223372036854775808).
• 3000000000U + 3000000000U: Adding two large positive numbers overflows and results in 0.
• 2147483647U - 4294967295U: Subtracting a large positive number from a smaller positive number results in a negative value (-2147483648).
• 65537U * 65537U: Multiplying two large numbers overflows and results in 0.

For 64-bit Unsigned Integers:

• //-18446744073709551615UL: The - operator cannot be applied to 64-bit unsigned integers; it will always give a compile-time error.
• 10000000000000000000UL + 10000000000000000000UL: Adding two large positive numbers overflows and results in 0.
• 9223372036854775807UL - 18446744073709551615UL: Subtracting a large positive number from a smaller positive number results in a negative value (-9223372036854775808L).
• 4294967296UL * 4294967296UL: Multiplying two large numbers overflows and results in 0.

Overflow Checking:

After the unchecked block, the code demonstrates overflow checking in C#. When checked overflow checking is enabled (i.e., not within an unchecked block), any integer overflow will result in an OverflowException being thrown.

• i + 1: Adding 1 to the maximum 32-bit signed integer value results in an overflow.
• checked { Console.WriteLine(i + 1); }: Attempting to add 1 to the maximum 32-bit signed integer value within a checked block throws an OverflowException.

using System;
    
public class IntegerOverflow
{
    public static void Main() {
        unchecked {
            Console.WriteLine("For 32-bit signed integers:");
            Console.WriteLine(-(-2147483647 - 1));
            Console.WriteLine(2000000000 + 2000000000);
            Console.WriteLine(-2147483647 - 2147483647);
            Console.WriteLine(46341 * 46341);
            Console.WriteLine((-2147483647 - 1) / -1);
            Console.WriteLine();
            
            Console.WriteLine("For 64-bit signed integers:");
            Console.WriteLine(-(-9223372036854775807L - 1));
            Console.WriteLine(5000000000000000000L + 5000000000000000000L);
            Console.WriteLine(-9223372036854775807L - 9223372036854775807L);
            Console.WriteLine(3037000500L * 3037000500L);
            Console.WriteLine((-9223372036854775807L - 1) / -1);
            Console.WriteLine();

            Console.WriteLine("For 32-bit unsigned integers:");
            //Negating a 32-bit unsigned integer will convert it to a signed 64-bit integer.
            Console.WriteLine(-4294967295U);
            Console.WriteLine(3000000000U + 3000000000U);
            Console.WriteLine(2147483647U - 4294967295U);
            Console.WriteLine(65537U * 65537U);
            Console.WriteLine();

            Console.WriteLine("For 64-bit unsigned integers:");
            // The - operator cannot be applied to 64-bit unsigned integers; it will always give a compile-time error.
            //Console.WriteLine(-18446744073709551615UL);
            Console.WriteLine(10000000000000000000UL + 10000000000000000000UL);
            Console.WriteLine(9223372036854775807UL - 18446744073709551615UL);
            Console.WriteLine(4294967296UL * 4294967296UL);
            Console.WriteLine();
        }
        
        int i = 2147483647;
        Console.WriteLine(i + 1);
        try {
            checked { Console.WriteLine(i + 1); }
        } catch (OverflowException) {
            Console.WriteLine("Overflow!");
        }
    }
    
}