Rearrange the given source code

Given a string str which contains the source code (C/C++/Java code) which is not arranged in a proper way, the task is to format that code in a proper way and print the result.

Examples:

Input: str = "#include<stdio.h>int main(){ cout << \"geeksforgeeks\" }"
Output:
#include<stdio.h>
int main()
{
 cout << "geeksforgeeks" 
}

Input: str = "#include<stdio.h>int main() { int a, b, c; c=a+b; printf(\"%d\", c); return 0; }"
Output:
#include<stdio.h>
int main() 
{
 int a, b, c;
 c=a+b;
 printf("%d", c);
 return 0;

}

Approach: Check various conditions like #, {, }, (, ), <, >, ; and format the code as required. If no changes are required or the code cannot be formatted then print the code as it is.

Below is the implementation of the above approach:

C++

// CPP program to rearrange the given source code
#include <bits/stdc++.h>
using namespace std;

// Function to rearrange the code
void rearrange(string str)
{
    string replaced;

    int Open_paren = 0, Open_Braces = 0;
    int Lessrthan = 0, i = 0, j = 0;

    do {

        // Various Conditions For The Code
        if (str[i] == '#' || str[i] == '<' || str[i] == '>'
            || str[i] == ';' || str[i] == '}' || str[i] == '{'
            || str[i] == '(' || str[i] == ')') {

            // Check for opening braces
            if (str[i] == '{')
                Open_Braces++;

            // Check for closing braces
            if (str[i] == '}')
                Open_Braces--;

            // For less than symbol
            if (str[i] == '<' && Open_paren == 0)
                Lessrthan++;

            // For greater than symbol
            if (str[i] == '>' && Open_paren == 0)
                Lessrthan--;

            // For open parenthesis
            if (str[i] == '(') {
                Lessrthan = 0;
                Open_paren++;
            }

            // For closing parenthesis
            if (str[i] == ')')
                Open_paren--;

            if (Open_paren > 0) {
                replaced += str[i];
            }
            else {

                // Replace the plain code
                // for closing parenthesis
                if (str[i] == ')')
                    replaced += str[i];

                // Replace the code for open and close braces
                else if (str[i] == '{' || str[i] == '}') {
                    replaced += '\n';
                    replaced += str[i];
                    replaced += '\n';
                }
                else if (Lessrthan > 0)
                    replaced += str[i];

                // Replace the code for # symbol
                else if (str[i] == '#') {
                    replaced += '\n';
                    replaced += str[i];
                }
                else {
                    replaced += str[i];
                    replaced += '\n';
                }
            }
        }

        // If all conditions do not
        // work then print the code as it is
        else {
            replaced += str[i];
        }

        i++;

    } while (i < str.length());
    replaced += '\0';

    // Print formatted code
    for (i = 0; i < replaced.length(); i++)
        cout << replaced[i];
    printf("\n");
}

// Driver Code
int main()
{

    string str = "#include<stdio.h>int main()"
                 "{ int a, b, c; c=a+b; printf(\"%d\", c);"
                 " return 0; }";

    // Function call
    rearrange(str);

    return 0;
}

Output:

#include<stdio.h>
int main()
{
 int a, b, c;
 c=a+b;
 printf("%d", c);
 return 0;
 
}