CP Stress Tester Generator

#!/usr/bin/env python3
"""
CP Stress Tester — generated by UtilityToolsLab
Finds the first counter-example between brute and optimal solutions.
"""
import subprocess, os, sys, tempfile

MAX_TESTS = 200

BRUTE_CODE = r"""
#include <bits/stdc++.h>
using namespace std;
int main(){
    int n; cin >> n;
    // brute force solution
    cout << n << endl;
}
"""

OPTIMAL_CODE = r"""
#include <bits/stdc++.h>
using namespace std;
int main(){
    int n; cin >> n;
    // optimal solution
    cout << n << endl;
}
"""

GEN_CODE = r"""
import random
import sys

# Generate random test case
n = random.randint(1, 100)
print(n)
"""

def write_file(path, content):
    with open(path, "w") as f:
        f.write(content)

def compile_cpp(src, out):
    result = subprocess.run(
        ["g++", "-O2", "-o", out, src],
        capture_output=True, text=True
    )
    if result.returncode != 0:
        print(f"Compile error:\n{result.stderr}")
        sys.exit(1)

def run_binary(binary, input_data):
    result = subprocess.run(
        [binary], input=input_data, capture_output=True, text=True, timeout=5
    )
    return result.stdout.strip()

def run_gen(gen_script):
    result = subprocess.run(
        [sys.executable, gen_script], capture_output=True, text=True, timeout=5
    )
    return result.stdout

def main():
    tmpdir = tempfile.mkdtemp()
    brute_src  = os.path.join(tmpdir, "brute.cpp")
    opt_src    = os.path.join(tmpdir, "optimal.cpp")
    gen_script = os.path.join(tmpdir, "gen.py")
    brute_bin  = os.path.join(tmpdir, "brute")
    opt_bin    = os.path.join(tmpdir, "optimal")

    print("Compiling brute force...")
    write_file(brute_src, BRUTE_CODE)
    compile_cpp(brute_src, brute_bin)

    print("Compiling optimal solution...")
    write_file(opt_src, OPTIMAL_CODE)
    compile_cpp(opt_src, opt_bin)

    write_file(gen_script, GEN_CODE)

    print(f"Running {MAX_TESTS} stress tests...\n")

    for t in range(1, MAX_TESTS + 1):
        test_input = run_gen(gen_script)
        out_brute  = run_binary(brute_bin,  test_input)
        out_opt    = run_binary(opt_bin,    test_input)

        if out_brute != out_opt:
            print(f"[COUNTER-EXAMPLE FOUND] Test #{t}")
            print(f"--- Input ---\n{test_input}")
            print(f"--- Brute Output ---\n{out_brute}")
            print(f"--- Optimal Output ---\n{out_opt}")
            with open("counter_example.txt", "w") as f:
                f.write(f"Input:\n{test_input}\nBrute:\n{out_brute}\nOptimal:\n{out_opt}")
            print("\nSaved to counter_example.txt")
            return

        if t % 50 == 0:
            print(f"  {t}/{MAX_TESTS} tests passed...")

    print(f"\n✅ All {MAX_TESTS} tests passed — no counter-example found!")

if __name__ == "__main__":
    main()