Question

#merge function
def merge(A, p, q, r):
    n1=q-p+1
    n2=r-q;
    L=[0]*(n1)
    R=[0]*(n2)

    for i in range(0,n1):
        L[i]=A[p+i]

    for j in range(0,n2):
        R[j]=A[q+j+1]

    L[i]=65000
    R[j]=65000
    i=0
    j=0
    for k in range(p,r+1):
        if L[i]<R[j] :
            A[k]=L[i]
            i+=1
        else:
            A[k]=R[j]
            j+=1




#merge sort function
def mergesort(A,p,r):
    if p<r:
        q=(p+(r-1))/2
        mergesort(A,p,q)
        mergesort(A,q+1,r)
        merge(A,p,q,r)




#calling mergesort
A=[5,4,3,2,1]


mergesort(A,0,len(A))
print(A)

我得到的错误：https://imgur.com/OAV2LbT

Traceback (most recent call last):
  File "<folder>\mergesort.py", line 44, in <module>
    mergesort(A,0,len(A)-1)
  File "<folder>\mergesort.py", line 35, in mergesort
    merge(A,p,q,r)
  File "<folder>\mergesort.py", line 19, in merge
    if L[i]<R[j] :
IndexError: list index out of range

Answer 1

for k in range(p,r+1):

由于您已将len(A)作为r的值传递，因此无需添加其他1：

for k in range(p,r):

有人能告诉我我的合并排序代码有什么问题吗？

1 个答案: