LintCode:丢失的第一个正整数

LintCode:丢失的第一个正整数

Python

from time import sleepclass Solution:    # @param A, a list of integers    # @return an integer    def firstMissingPositive(self, A):        # write your code here        if len(A) == 0:            return 1        m = 0        n = len(A)        while m < n:            if A[m] == m + 1:                m += 1            else:                if A[m] >= 0 and A[m] < n and A[m] != A[A[m] - 1]:                    #A[m], A[A[m] - 1] = A[A[m] - 1], A[m]                    A[A[m] - 1], A[m] = A[m] ,A[A[m] - 1]                else:                    m += 1        for i in range(n):            if A[i] != i + 1:                return i + 1        return n + 1