如何找到相加和给定总和的对应索引? 而且,是否可以处理大小为500000(较大大小)的元素的列表?
输入:
l1 = [9,1, 2, 7, 6, 1, 5]
target = 8
**Constraints**
1<=(len(l1))<=500000
1<=each_list_element<=1000
输出:
Format : {index:element}
{1:1, 5:1, 4:6} #Indices : 1,5,4 Elements : 1,1,6
{1:1, 2:2, 6:5}
{5:1, 2:2, 6:5}
{1:1, 3:7}
{5:1, 3:7}
{2:2, 4:6}
尝试过:
from itertools import combinations
def test(l1, target):
l2 = []
l3 = []
if len(l1) > 0:
for r in range(0,len(l1)+1):
l2 += list(combinations(l1, r))
for i in l2:
if sum(i) == target:
l3.append(i)
return l3
l1 = [9,1, 2, 7, 6, 1, 5]
target = 8
print(test(l1,target))
[(1, 7), (2, 6), (7, 1), (1, 2, 5), (1, 6, 1), (2, 1, 5)]
有人可以引导我吗?
更新
Apart from above, code fails to handle these scenarios
Input = [4,6,8,5,3]
target = 3
Outputs {} , need to output {4:3}
Input = [4,6,8,3,5,3]
target = 3
Outputs {} , need to output {5:3,3:3} #corrected index
Input = [1,2,3,15]
target = 15
Outputs = {}, need to output {3:15}
答案 0 :(得分:2)
您的代码很接近,我将使用枚举以元组对的形式获取索引和值。我总是删除任何索引和值元组,其中该值大于目标值,因为这不可能匹配。这将产生较少的组合。然后像您一样,我只遍历元组的排列并在每个排列中求和,如果它求和到目标,则产生该排列。最后在循环中输出值,我将烫发给字典以转换为所需的字典格式
HTTPStreamType
输出
interface MyCommonData {
foo: string
bar: number
}
interface WebSocketData extends MyCommonData {
type: 'WEBSOCKET'
connection: WebSocketType
}
interface HttpStreamData extends MyCommonData {
type: 'HTTP_STREAM';
connection: HTTPStreamType;
}
type MyData = WebSocketData | HttpStreamData
答案 1 :(得分:0)
您可以只使用索引函数来获取索引并将其存储为key:value对,并借助字典将其存储在另一个列表中,例如以下,
from itertools import combinations
def test(l1, target):
l2 = []
l3 = []
l4=[]
dict1={}
a=0
if len(l1) > 0:
for r in range(0,len(l1)+1):
l2 += list(combinations(l1, r))
for i in l2:
dict1={}
if sum(i) == target:
for j in i:
a=l1.index(j)
dict1[a]=j
l4.append(dict1)
l3.append(i)
return l4
l1 = [4,6,8,5,3]
target = 3
print(test(l1,target))
输出:
[{4: 3}]
如您所见,条件l1 = [4,6,8,5,3] target = 3
有效,以前不起作用。
希望这会有所帮助!