def add_includes(code: str, problem_id: str) -> str:
    """
    Fix common compilation errors for IOI problems.
    """
    if not code:
        return code
    # has most of the useful functions
    code_header = "#include <bits/stdc++.h>\n"
    # include the problem header
    problem_header_include = f'#include "{problem_id}.h"'
    if problem_header_include not in code:
        code_header += problem_header_include + "\n"
    # use namespace std since models forget std:: often
    if "using namespace std;" not in code and "std::" not in code:
        code_header += "\nusing namespace std;\n\n"
    return code_header + code

    Fix common compilation errors for IOI problems.
    
src/open_r1/utils/competitive_programming/ioi_utils.py