Nested for loop not running in python after the first iteration

Question

I have a nested for loop which is not running after the first iteration

N, M = map(int, input().split())
numbers = map(int, input().split())

dic = {}
for m in range(N):
  dic.setdefault(m,[])
  for n in numbers:
      if n % N == m:
      dic[m].append(n)
print(dic)

The above code is generating the following result {0: [3, 42], 1: [], 2: []} for the sample data down bellow:

3 5
1 3 8 10 42

However I would like to get {0: [3, 42], 1: [1, 10], 2: [8]}
What am I doing wrong?

Asked By: lucasbbs

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Source

Answer 1

The problem is that map returns an iterator, and you are consuming the iterator completely in the first outer loop. You need:

numbers = [int(k) for k in input().split()]

instead of using map.

Answered By: Tim Roberts

Answer 2

try this:

N, M = map(int, input().split())
numbers = [int(x) for x in input().split()]

dic = {}
for m in range(N):
    dic.setdefault(m,[])
    for n in numbers:
        print(n % N)
        if n % N == m:
            dic[m].append(n)
print(dic)

Answered By: Ahmar Shoeb

Nested for loop not running in python after the first iteration

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