Maximum of three values in C++ [closed]

If you have access to C++11, I'd suggest using std::max with an initializer_list<T>. A complete minimal example:

#include <algorithm>
#include <initializer_list>
#include <iostream>

int main()
{
    int a = 1;
    int b = 2;
    int c = 3;

    int m = std::max({a, b, c});

    std::cout << m << "\n";
}

Assuming you have an unknown set of data, you can always place it in an array / vector / list and run...

int res = *max_element( intList.begin(),  intList.end() ); //where intList is the list

Which is as commented by @Yuushi : but expended on, since it can get quirky

#include <algorithm>
#include <iostream>
#include <list>
#include <stdlib.h> 
#include <algorithm>    // std::max

using namespace std;

int main() {
   list<int> intList;
   int a, b;
   int maxItems = rand() % 40 + 10; //10 to 50 items

   cout << "=== Testing a maximum of " << maxItems << " values ===\n"; 
   cout << "generating random value set: {";

   for( a = 0; a < maxItems; ++a ) {
      b = rand() % 100;
      cout << b << ", ";
      intList.push_back(b);
   }
   cout << "}\n";

   //Note max element inputs iterators, and outputs the max value iterator! 
   //-> which is the pointer to the actual value (hence * to get value)
   a = *max_element( intList.begin(),  intList.end() );
   cout << "max value generated = " << a << "\n";

   return 0;
}

Which can give a sample result as below

=== Testing a maximum of 33 values ===
generating random value set: {86, 77, 15, 93, 35, 86, 92, 49, 21, 62, 27, 90, 59, 63, 26, 40, 26, 72, 36, 11, 68, 67, 29, 82, 30, 62, 23, 67, 35, 29, 2, 22, 58, }
max value generated = 93

A simpler way would be to use this overloaded function std::max that accepts an object of the type std::initializer_list<int>

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    int a = 2;
    int b = 3;
    int c = 4;
    cout << max({a,b,c}) << '\n';

    cout << max({7,7,8}) << '\n';

return 0;
}