942. DI String Match

class Solution:
    def diStringMatch(self, S: str) -> List[int]:
        A=[i for i in range(len(S)+1)]
        res = A
        for index,s in enumerate(S):
            if s is 'I':
                A[index] =res[0]
                res = res[1:]
            if s is 'D':
                a = res[-1]
                res = res[0:-1]
                A[index] = a
        A[-1]=res[0]        
                
        return A

　　1224ms,14.1M