from collections import Counter

ciphertext = "KHOOR ZRUOG WKLV LV D WHVW"
clean = ''.join(c for c in ciphertext.upper() if c.isalpha())
freq = Counter(clean)
total = len(clean)

print(f"{'Letter':8} {'Count':6} {'Freq%':8}")
print("-" * 24)
for letter, count in sorted(freq.items(), key=lambda x: -x[1]):
    print(f"  {letter}      {count:4d}    {count/total*100:5.1f}%")

english_freq_order = "ETAOINSHRDLCUMWFGYPBVKJXQZ"
cipher_freq_order  = ''.join(l for l, _ in sorted(freq.items(), key=lambda x: -x[1]))

print(f"English:    {english_freq_order}")
print(f"Ciphertext: {cipher_freq_order}")
# Most frequent in cipher → likely 'E'
# Second most frequent → likely 'T'

# Start with frequency-based guesses
mapping = {}
for cipher_char, eng_char in zip(cipher_freq_order, english_freq_order):
    mapping[cipher_char] = eng_char

# Apply mapping
def apply_mapping(text, mapping):
    return ''.join(mapping.get(c, '_') if c.isalpha() else c for c in text.upper())

decrypted = apply_mapping(ciphertext, mapping)
print(decrypted)

# Refine: look at common words, digrams, trigrams
# Update mapping interactively until it makes sense
mapping['K'] = 'H'   # manual refinement
mapping['O'] = 'E'
mapping['R'] = 'L'

Single-letter words: A or I
Two-letter words: IT, IN, IS, AN, OR, TO, OF, AT, BE, WE, HE
Three-letter words: THE (most common!), AND, FOR, ARE, BUT, NOT
Common digrams: TH, HE, IN, ER, AN, RE, ON, EN
Common trigrams: THE, AND, ING, ION, ENT, FOR

# Find candidate single-letter words
words = ciphertext.split()
single = [w for w in words if len(w) == 1]
print("Single-letter words:", set(single))
# If "D" appears as a single letter → D probably means "a" or "i"