423. Reconstruct Original Digits from English

class Solution:
    def originalDigits(self, s: str) -> str:
        """
        zero  z
        one     o 1-0-2-4
        two   w
        three   t 3-2-8
        four  u
        five    f 5-4
        six   x
        seven   s 7-6
        eight g
        nine    i 9-8-6-5
        
        """
        # step1 c  
        cnt = [0] * 10
        # first even then odd 
        for c in s:
            if c == 'z':
                cnt[0] += 1
            elif c == 'w':
                cnt[2] += 1
            elif c == 'u':
                cnt[4] += 1
            elif c == 'x':
                cnt[6] += 1
            elif c == 'g':
                cnt[8] += 1
                
            elif c == 'o':
                cnt[1] += 1
            elif c == 't':
                cnt[3] += 1
            elif c == 'f':
                cnt[5] += 1
            elif c == 's':
                cnt[7] += 1
            elif c == 'i':
                cnt[9] += 1
        # step2 process odd numbser
        cnt[5] = cnt[5]-cnt[4]
        cnt[7] = cnt[7]-cnt[6]
        cnt[1] = cnt[1]-cnt[0]-cnt[2]-cnt[4]
        cnt[9] = cnt[9]-cnt[8]-cnt[6]-cnt[5]
        cnt[3] = cnt[3]-cnt[8]-cnt[2]

        
        # step3, join string together
        res = []
        for num in range(len(cnt)):
            if cnt[num] != 0:
                res.append(str(num)* cnt[num])
        return ''.join(res)