AlgorithmsByPython/MergeSort.py at master · DouTong/AlgorithmsByPython · GitHub

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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)
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defmergeSort(alist):
iflen(alist) >1:
mid=len(alist)//2
lefthalf=alist[:mid]
righthalf=alist[mid:]

mergeSort(lefthalf)
mergeSort(righthalf)

i=0; j=0; k=0
whilei<len(lefthalf) andj<len(righthalf):
iflefthalf[i] <righthalf[j]:
alist[k] =lefthalf[i]
i+=1
else:
alist[k] =righthalf[j]
j+=1
k+=1

whilei<len(lefthalf):
alist[k] =lefthalf[i]
i+=1
k+=1
whilej<len(righthalf):
alist[k] =righthalf[j]
j+=1
k+=1

alist= [54,26,93,17,77,31,44,55,20]
mergeSort(alist)
print(alist)