Question

我想编写一个python程序，它必须计算数组中相邻位置的重复元素。我想显示出现次数。

# Example 
alist=[1,2,2,3,3,5,6]  # ----- output - 4
alist=[1,2,3,4] # -------------output - 0
alist=[4,5,6,6,8,8,8,8] # -------output - 8

我试过

alist=[1,20,4,4,4,50];
i =0;
nextele=0;
temp=0;

while(i < len(alist)):
  'print(alist[i])'
   temp = alist[i];
   nextele =alist[i+1];\\here i am getting error out of bound when it iterates last elelment
  i=i+1;

提前致谢---

Answer 1

在遍历列表时使用for x in range(len(aList)-1)以防止获得IndexError。比较aList[x]和aList[x+1]，如果它们相同，则将计数器增加2。

c=0
for x in range(len(aList)-1):
    if aList[x]==aList[x+1]:
        c+=2

Answer 2

因为for循环中有alist[i+1]，所以你不能通过列表直到结束，所以你必须在结束之前结束一个元素：

for i in range(len(alist)-1):
    if(alist[i] == alist[i+1]):
        counter+=2    # since you count both elements

alist=[1,2,2,3,3,5,6] # 4
alist=[4,5,6,6,8,8,8,8] # 8

Answer 3

执行此操作的有效方法是将sum与生成器表达式一起使用，alist与alist[1:]一起使用，以便我们可以比较alist的相邻项。

data = [
    [1, 2, 2, 3, 3, 5, 6],
    [1, 2, 3, 4],
    [4, 5, 6, 6, 8, 8, 8, 8],
    [1, 20, 4, 4, 4, 50],
]

for alist in data:
    a = sum(2 for u, v in zip(alist, alist[1:]) if u == v)
    print(alist, a)

<强>输出

[1, 2, 2, 3, 3, 5, 6] 4
[1, 2, 3, 4] 0
[4, 5, 6, 6, 8, 8, 8, 8] 8
[1, 20, 4, 4, 4, 50] 4

如果您确实需要重复项目的总计数，则可以使用列表推导（或生成器表达式）和itertools.groupby来查找重复的组，然后使用另一个生成器表达式来汇总包含更多项的组的长度超过1个元素。

from itertools import groupby

data = [
    [1, 2, 2, 3, 3, 5, 6],
    [1, 2, 3, 4],
    [4, 5, 6, 6, 8, 8, 8, 8],
    [1, 20, 4, 4, 4, 50],
]

for alist in data:
    runs = [len(list(g)) for _, g in groupby(alist)]
    repeats = sum(u for u in runs if u > 1)
    print(alist, repeats)

<强>输出

[1, 2, 2, 3, 3, 5, 6] 4
[1, 2, 3, 4] 0
[4, 5, 6, 6, 8, 8, 8, 8] 6
[1, 20, 4, 4, 4, 50] 3

列表理解可以与生成器表达式结合使用：

for alist in data:
    repeats = sum(u for u in (len(list(g)) for _, g in groupby(alist)) if u > 1)
    print(alist, repeats)

Answer 4

def get_count(num_list):
    count=0
    i=0

    while(i<(len(num_list)-1)):
        if(num_list[i]==num_list[i+1]):
            count+=1
        i+=1

    return count

num_list=[1,1,5,100,-20,-20,6,0,0]
print(get_count(num_list))

Answer 5

lis=[0,1,1,0,1,2,2,3]                #list declared
count=0                          #count initialised
for i in range(len(lis)-1):
       if lis[i]==lis[i+1]:      #checking the value with the adjacent values
              count+=1
print(count)

Python程序查找数组中重复相邻元素的计数

5 个答案: