Problème
This is the advanced follow-up to Flatten a 2D Array. Practice that challenge first. Here lists may contain more lists at any depth. In C++ and C#, use the NestedValue type in the starter code. Read kind first: 0 means skip this entry, 1 means append value, and 2 means visit items recursively.
Turn a nested list into a flat list of integers. Read from left to right; whenever you reach another list, read its contents before continuing. Ignore null values (shown as None in examples) and empty lists. Preserve repeated integers and their order.
Python receives ordinary nested lists containing integers and None. C++ and C# receive a list of NestedValue objects supplied by the starter: kind 0 means null, kind 1 means integer in value, and kind 2 means a list in items. Only the field selected by kind matters. Return a plain integer list in every language.
Implement flatten_arbitrarily_nested_list(values).
Input
values: A list whose entries can be integers, null, or further lists.
Output
Return the integers in depth-first, left-to-right order. Return an empty list when there are no integers.
Contraintes
The outer value is a list. At most 10,000 entries across all lists; maximum nesting depth 50. Integer leaves fit signed 64-bit. Leaves are integers or null, never strings or booleans.
Exemples
Entrée :
values = [
1,
[
2,
None,
[3]
],
[],
4
]
Sortie attendue :
expected = [1, 2, 3, 4]Utilisez le type NestedValue fourni dans le code de départ. Ses champs sont kind (0 = null, 1 = entier, 2 = liste), value (l'entier), et items (la liste imbriquée).
Entrée :
std::vector<NestedValue> values = {
NestedValue{1, 1, {}},
NestedValue{2, 0, {
NestedValue{1, 2, {}},
NestedValue{0, 0, {}},
NestedValue{2, 0, {
NestedValue{1, 3, {}}
}}
}},
NestedValue{2, 0, {}},
NestedValue{1, 4, {}}
};
Sortie attendue :
std::vector<long long> expected = {1, 2, 3, 4};Utilisez le type NestedValue fourni dans le code de départ. Ses champs sont kind (0 = null, 1 = entier, 2 = liste), value (l'entier), et items (la liste imbriquée).
Entrée :
NestedValue[] values = new NestedValue[] {
new NestedValue { kind = 1, value = 1 },
new NestedValue { kind = 2, items = new NestedValue[] {
new NestedValue { kind = 1, value = 2 },
new NestedValue { kind = 0 },
new NestedValue { kind = 2, items = new NestedValue[] {
new NestedValue { kind = 1, value = 3 }
} }
} },
new NestedValue { kind = 2, items = new NestedValue[] {} },
new NestedValue { kind = 1, value = 4 }
};
Sortie attendue :
long[] expected = new long[] {1, 2, 3, 4};Explication
Read 1, then enter the nested list and read 2 and 3, skipping null. The empty list adds nothing; finish with 4.
Entrée :
values = [
None,
[],
[None]
]
Sortie attendue :
expected = []Utilisez le type NestedValue fourni dans le code de départ. Ses champs sont kind (0 = null, 1 = entier, 2 = liste), value (l'entier), et items (la liste imbriquée).
Entrée :
std::vector<NestedValue> values = {
NestedValue{0, 0, {}},
NestedValue{2, 0, {}},
NestedValue{2, 0, {
NestedValue{0, 0, {}}
}}
};
Sortie attendue :
std::vector<long long> expected = {};Utilisez le type NestedValue fourni dans le code de départ. Ses champs sont kind (0 = null, 1 = entier, 2 = liste), value (l'entier), et items (la liste imbriquée).
Entrée :
NestedValue[] values = new NestedValue[] {
new NestedValue { kind = 0 },
new NestedValue { kind = 2, items = new NestedValue[] {} },
new NestedValue { kind = 2, items = new NestedValue[] {
new NestedValue { kind = 0 }
} }
};
Sortie attendue :
long[] expected = new long[] {};Explication
Every entry is null or an empty container. No integer remains.
Références
Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.