#include <vector>
//#include <cassert>
#include <numeric>
#include <iostream>
#include <algorithm>
//#include <functional>
 
void printVec(const std::vector<int> &vec)
{
    std::cout << "v= {";
    for (int i : vec)
        std::cout << i << ", ";
    std::cout << "}\n";
}
 
int main()
{
    float percentile = 0.5;
    std::vector<int> vec{14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
    std::vector<int>* seq = &vec;
    printVec(*seq);
    int res = -1;
    
//    std::vector<int>::iterator b = seq->begin();
//    std::vector<int>::iterator e = seq->end();

//    std::vector<int>::iterator m = b;
    std::vector<int>::iterator nth = seq->begin();
  
//    std::cout << "v.size()/2: "  << v.size()/2 << '\n';
//    //auto m = v.begin() + v.size()/2;
//    std::advance(m, v.size() / 2);
    
    const std::size_t pos = percentile * std::distance(seq->begin(), seq->end());
    
    std::cout << "std::distance(b, e): " << std::distance(seq->begin(), seq->end()) << '\n';
    std::cout << "pos: " << percentile * std::distance(seq->begin(), seq->end()) << '\n';

    std::advance(nth, pos);
    
//    std::nth_element(v.begin(), m, v.end());
//    std::cout << "\nThe median is " << v[v.size()/2] << '\n';
//    // The consequence of the inequality of elements before/after the Nth one:
//    assert(std::accumulate(v.begin(), m, 0) < std::accumulate(m, v.end(), 0));
//    printVec(v);
    
    std::nth_element(seq->begin(), nth, seq->end());
    res = seq->at(pos);
    
    std::cout << "\nThe quantile is " << res << '\n';
    // The consequence of the inequality of elements before/after the Nth one:
//    assert(std::accumulate(seq->begin(), nth, 0) < std::accumulate(nth, seq->end(), 0));
    printVec(*seq);
    
}
by

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}