Flatten Arbitrarily Nested Lists (Recursion) प्रोग्रामिंग चैलेंज

समस्या

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.

सीमाएँ

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.

उदाहरण

उदाहरण 1

इनपुट:
values = [
    1,
    [
        2,
        None,
        [3]
    ],
    [],
    4
]

अपेक्षित आउटपुट:
expected = [1, 2, 3, 4]

स्टार्टर कोड में दिए गए NestedValue टाइप का उपयोग करें। इसके फील्ड हैं: kind (0 = null, 1 = integer, 2 = list), value (integer), और items (nested list)।

इनपुट:
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, {}}
};

अपेक्षित आउटपुट:
std::vector<long long> expected = {1, 2, 3, 4};

इनपुट:
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 }
};

अपेक्षित आउटपुट:
long[] expected = new long[] {1, 2, 3, 4};

व्याख्या

Read 1, then enter the nested list and read 2 and 3, skipping null. The empty list adds nothing; finish with 4.

उदाहरण 2

इनपुट:
values = [
    None,
    [],
    [None]
]

अपेक्षित आउटपुट:
expected = []

इनपुट:
std::vector<NestedValue> values = {
    NestedValue{0, 0, {}},
    NestedValue{2, 0, {}},
    NestedValue{2, 0, {
        NestedValue{0, 0, {}}
    }}
};

अपेक्षित आउटपुट:
std::vector<long long> expected = {};

इनपुट:
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 }
    } }
};

अपेक्षित आउटपुट:
long[] expected = new long[] {};

व्याख्या

Every entry is null or an empty container. No integer remains.

संदर्भ

यह चुनौती CodeUtility के लिए अनुकूलित की गई है। ऊपर दिए गए स्टेटमेंट और सीमाओं का पालन करें।

Exercism: Flatten Array

Flatten Arbitrarily Nested Lists (Recursion)

समस्या

Input

Output

सीमाएँ

उदाहरण

व्याख्या

व्याख्या

संदर्भ

समुदाय समाधान