txt = "xpbctbxabacbxtbpqa"
pat = "tbapxab"
m = len(pat)
n = len(txt)
R = [m for _ in range(0, 26)]

def alpha_number(char):
    return ord(char) - 97

for i in range(m):
    R[alpha_number(pat[i])] = i

j = 0
while j < n-m:
    for i in range(m-1, -1, -1):
        print(j)
        match = pat[i] == txt[j+i]
        if match:
            pass
            # print(i)
        else:
            mismatched = txt[j+i]
            shift = i-R[alpha_number(mismatched)]
            j += max(1, shift)
            if j > n-m:
                break
print(R)