#include <iostream>

// In many applications, a value must be restricted to
// lie within a specified interval.
//
// For example, suppose that a value 'x' must be restricted
// to the interval
//
//     [-bound, bound].
//
// If 'x' is greater than 'bound', replace it with 'bound'.
// If 'x' is less than '-bound', replace it with '-bound'.
// Otherwise, leave 'x' unchanged.
//
// This operation is often called "clipping" or "saturation."
// Mathematically, we can define
//
//                 / -bound, if x < -bound,
//                 |
//     clip(x) =  <    x,    if -bound <= x <= bound,
//                 |
//                 \  bound, if x > bound.
//
// For example, if bound = 5:
//
//     x =  8.2    ->    clip(x) =  5
//     x =  5.0    ->    clip(x) =  5
//     x =  3.7    ->    clip(x) =  3.7
//     x =  0.0    ->    clip(x) =  0
//     x = -2.4    ->    clip(x) = -2.4
//     x = -5.0    ->    clip(x) = -5
//     x = -9.1    ->    clip(x) = -5
//
// The graph of this function is:
//
//
//          bound                  |   ________________
//                                 |  /
//                                 | /
//                                 |/
//             - - - - - - - - - - + - - - - - - - - - - x
//                                /|0
//                               / |
//        -bound ________________/  |
//                                 |
//
//
// Notice the three portions of the graph:
//
//     1. For x < -bound, the output is constant at -bound.
//
//     2. For -bound <= x <= bound, the output equals x.
//
//     3. For x > bound, the output is constant at bound.
//
// Write a program that asks the user for 'x' and a
// non-negative value 'bound' and then prints clip(x).
//
// If the user enters a negative value for 'bound',
// immediately terminate the program by returning 0
// from main().

// Function declarations
int main();

// Function definitions
int main() {
    double x{};

    std::cout << "Enter a number 'x': ";
    std::cin >> x;

    double bound{};

    std::cout << "Enter a non-negative bound: ";
    std::cin >> bound;

    if ( bound < 0.0 ) {
        return 0;
    }

    // There are three possibilities corresponding to
    // the three portions of the graph.

    if ( x > bound ) {
        // 'x' is above the permitted interval, so clip
        // it to the upper bound.

        std::cout << "clip(x) = " << bound << std::endl;
    } else if ( x < -bound ) {
        // 'x' is below the permitted interval, so clip
        // it to the lower bound.

        std::cout << "clip(x) = " << -bound << std::endl;
    } else {
        // We now know that
        //
        //     -bound <= x <= bound,
        //
        // so 'x' is already within the permitted interval.

        std::cout << "clip(x) = " << x << std::endl;
    }

    return 0;
}