from typing import Dict


def normalize_score(score: Dict[int, float]) -> Dict[int, float]:
    """Normalize input score between min (=0) and max (=1)"""
    max_s = max(score.values())
    min_s = min(score.values())
    delta = max_s - min_s if max_s != min_s else 1
    return {key: (val - min_s) / delta for key, val in score.items()}