/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

#include <iostream>
#include <string.h>
#include <vector>
#include <iomanip>
#include <sstream>

using namespace std;

inline string hex_to_string(uint8_t* hex, int size)
{
  stringstream ss;

  ss << hex << setfill('0');
  for (int i = 0; i < size*2; i++) {
    ss << setw(2) << static_cast<unsigned>(hex[i]);
  }
  return ss.str();
}

uint8_t* HexToBytes(const string& hex) {
  vector<uint8_t> bytes;
  for (unsigned int i = 0; i < hex.length(); i += 2) {
    string byteString = hex.substr(i, 2);
    uint8_t byte = (uint8_t) strtol(byteString.c_str(), nullptr, 16);
    bytes.push_back(byte);
  }
  printf("### (in helpers.h) Target packet is\n%s\n", hex_to_string(bytes.data(), hex.length()).c_str());
  return bytes.data();
}


int main()
{
    string hex = "450000474144400040113d40ac10000208080808c86d003500335bce674a010000010000000000010377777706676f6f676c6503636f6d00000100010000290200000000000000";
    uint8_t buf[71 + 1];
    int* p;
    // p = HexToBytes(hex);
    memcpy(p, HexToBytes(hex), 71);
    
    // printf("%s\n", hex_to_string((uint8_t*)p, 71).c_str());
    
    // for (int i = 0; i < 72; i++) {
    //     printf("%c", buf[i]);
    // }
    // printf("\n");

    return 0;
}

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
}