Question

Write a C++ program that overloads a function named LinearSearch that searches an array of data of either integer data type, float, or double for a specific data. Test it in main by creating and assigning values to an array of integers, float, and double and searching each of them for some specific data.Please circle the part that is doing function/operator overloading and explain the advantages of using function/operator overloading in your code.

Answer 1

Explanation:

#include <iostream>

#include <vector>

#include <iomanip>

using namespace std;

/*

Overloading means equal function name with different call prototype each.

It's a useful tool that lets you think once and write similar role code twice or more times keeping equal function name.

Please look at lines 12-14: they are overloaded call prototype versions of LinearSearch with identical mission (to know if a value is present in a set)

*/

//#define GENERICS

#ifndef GENERICS                                                                // Conditional compilation statement

bool LinearSearch(vector<int>   ,int);

bool LinearSearch(vector<float> ,float);

bool LinearSearch(vector<double>,double);

#else                                                                           // Conditional compilation statement (uncomment line 10 statement)

template <typename genType>

bool LinearSearch(vector<genType> v, genType value);                            // LinearSearch (generic type parameters version)

#endif

int main(int argc, char *argv[]) {                                              // Test code follows:    

vector<int> vInt    {1,                     -2,     3,          -4,     5};     // Test data (int)

vector<float> vFlo  {1.23456f,              -2.35f, 3.1416f,    -4.7f,  5.55f}; // Test data (float)

vector<double> vDou {1.234567890123456789,  -2.35,  3.1415927,  -4.7,   5.55};  // Test data (double)

cout <<3 << "        is " << (LinearSearch(vInt,3)      ?"":"not ") << "in: {";for(auto x:vInt) cout << setw(11) << x;cout << "}\n";

cout <<3.1416f<< "   is " << (LinearSearch(vFlo,3.1416f)?"":"not ") << "in: {";for(auto x:vFlo) cout << setw(11) << x;cout << "}\n";

cout <<3.14   << " is " << (LinearSearch(vDou,3.1416) ?"":"not ") << "in: {";for(auto x:vDou) cout << /*setprecision(9)<<*/setw(11) << x;cout << "}\n";

return 0;

}

#ifndef GENERICS

// Overloaded function code follows:

bool LinearSearch(vector<int> v, int value) {                                   // LinearSearch (integer parameters version)

bool found = false;                                                             // Until now we haven't found the value we are searching for,

for(auto x:v) found = found || x == value;                                      // but if it is here found becomes true.

return(found);

}

bool LinearSearch(vector<float> v, float value) {                               // LinearSearch (float parameters version)

bool found = false;

for(auto x:v) found = found || x == value;

return(found);

}

bool LinearSearch(vector<double> v, double value) {                             // LinearSearch (double float parameters version)

bool found = false;

for(auto x:v) found = found || x == value;

return(found);

}

/*

So far, so good. It works! But, despite there was little effort involved, redundant code remains.

Is there any solution? Yes! It's called generic programming.

*/

#else

/*

Consider the following code:

   - Template statement at first accepts a generic type as a parameter (genType)

   - genType is used for both parameters (array and value to search)

   - Template statements located after generic version of LinearSearch instructs compiler to generate each type version

Conclusions:    

   - Compared with overloaded versions generic code is more elegant and avoids completely redundancy

   - It enhances overloading while keeping its advantages

*/

template <typename genType>

bool LinearSearch(vector<genType> v, genType value) {   // LinearSearch (generic type parameters version)

bool found = false;                                     // Until now we haven't found the value we are searching for,

for(auto x:v) found = found || x == value;              // but if it is here found becomes true.

return(found);

}

template bool LinearSearch(vector<int>   ,int);

template bool LinearSearch(vector<float> ,float);

template bool LinearSearch(vector<double>,double);

#endif

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