#复杂度为n平方
def MaxSubseqSum1(A , N ): ThisSum=0 MaxSum = 0 for i in range(0,N): ThisSum=0 for j in range(i,N):

ThisSum=0

for k in range(i,j):

         ThisSum+=A[j]
         if ThisSum>MaxSum:
             MaxSum=ThisSum
 print( MaxSum)    

A=[ -2, 11, -4, 13, -5, -2 ]
N=len(A)
t= MaxSubseqSum1(A , N )

#复杂度更低 n 在线处理

def MaxSubseqSum1(A , N ): ThisSum=0 MaxSum = 0 for i in range(0,N): ThisSum+=A[i]

      if ThisSum>MaxSum:
             MaxSum=ThisSum
      elif ThisSum<0:
          ThisSum=0
 print( MaxSum)    

A=[ -1, 3, -2, 4, -6, 1,6,-1 ]
N=len(A)
t= MaxSubseqSum1(A , N )