47. Mode Selection Enum

Declare a scoped enum class named Mode representing GPIO operating modes with exactly four values, defined in the following order:

• Input
• Output
• PullUp
• PullDown

The enum must use uint8_t as its underlying type.

Implement a function:

const char* toString(Mode m);

This function must return the following string representations:

• Mode::Input → "INPUT"
• Mode::Output → "OUTPUT"
• Mode::PullUp → "PULLUP"
• Mode::PullDown → "PULLDOWN"

The program will read an integer value from standard input.

The input value is guaranteed to be in the range 0 to 3, where:

• 0 maps to Mode::Input
• 1 maps to Mode::Output
• 2 maps to Mode::PullUp
• 3 maps to Mode::PullDown

After mapping the integer to the corresponding enum value, print the string representation using toString().

Input

A single integer value in the range 0 to 3 (inclusive).

Output

A single uppercase string representing the corresponding GPIO mode.

Example 1

Input:

0

Output:

INPUT 

Example 2

Input:

2

Output:

PULLUP 

Constraints

• Input integer x is guaranteed to be in the range 0 ≤ x ≤ 3
• Enum underlying type must be uint8_t
• No dynamic memory allocation is allowed
• toString() must return string literals (no std::string)
• Program must compile under C++11 or later
• Execution must be deterministic with no undefined behavior
• Only standard headers <iostream> and <cstdint> may be used