Merkkijono

input/code.cpp: In function 'int main()':
input/code.cpp:12:28: error: variable-sized object 'str' may not be initialized
     char str[len+1] = {'\0'};
                            ^
input/code.cpp:17:33: error: variable-sized object 'str2' may not be initialized
         char str2[len+1] = {'\0'};
                                 ^
input/code.cpp:20:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0; i<len;i++)
                          ^

#include <iostream>
#include <cstring>
#define MAX_LENGTH 10000000
using namespace std;

int main()
{
    char* sin = new char[MAX_LENGTH];
    cout << ">";
    cin >> sin;
    size_t len = strlen(sin);
    char str[len+1] = {'\0'};
    strcpy(str,sin);
    delete [] sin;
    while(true)
    {
        char str2[len+1] = {'\0'};
        int f = 0;
        int strc = 0;
        for(int i = 0; i<len;i++)
        {
            if(f==0) 
            {
                if(str[i] == str[i+1])
                {   
                    f++;
                }
                else
                {
                    str2[strc] = str[i];
                    strc++;
                }
            }
            else if (f==1)
            {
                if(str[i] != str[i-1])
                {
                    str2[strc] = str[i];
                    strc++;
                    f++;
                }
            }
            else
            {
                str2[strc] = str[i];
                strc++;
            }
        }
        strcpy(str,str2); 
        if(f == 0) break;
    }
    cout << str << "\n\0";
}