Description
Report the first missing literal edge with matched prefix; a fully matched nonterminal path is structurally present, not a missing edge.
A trie stores literal words as root-to-node character paths, with terminal flags marking complete words. A terminal can also have children, and an existing prefix path need not be a stored word. This family uses one UTF-16 code unit per ordinary edge, so code-unit length differs from a displayed character or Unicode code-point count.
Report the first missing literal edge with matched prefix; a fully matched nonterminal path is structurally present, not a missing edge.
When to use this tool
Use this tool to report the first missing literal edge with matched prefix; a fully matched nonterminal path is structurally present, not a missing edge.
How to use the tool and how it works
- Enter nodesJson, query using the definitions below. Serialize JSON text fields in the decoded shape shown below.
- Run the operation. Resolve input-format errors before interpreting an output.
- Read result.witness, using the stated boundary, ordering, sign and absence conventions.
Follow the query from root node zero. On the first missing edge return its code-unit position, missing character and already matched prefix; return null if every edge exists.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| nodesJson | JSON array of {id,parent,character,terminal} nodes under the complete root-zero trie rules below. | Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply. |
| query | Literal query text to follow one UTF-16 code unit per edge. | Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply. |
These decoded structures show the examples inside JSON text fields. Supply their serialized JSON strings as input.
{
"nodesJson": [
{
"id": 0,
"parent": null,
"character": "",
"terminal": false
},
{
"id": 1,
"parent": 0,
"character": "a",
"terminal": true
},
{
"id": 2,
"parent": 1,
"character": "b",
"terminal": true
},
{
"id": 3,
"parent": 0,
"character": "b",
"terminal": true
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.witness | First missing code-unit position/character/prefix, or null when the entire path exists. |
{
"input": {
"nodesJson": "[{\"id\": 0, \"parent\": null, \"character\": \"\", \"terminal\": false}, {\"id\": 1, \"parent\": 0, \"character\": \"a\", \"terminal\": true}, {\"id\": 2, \"parent\": 1, \"character\": \"b\", \"terminal\": true}, {\"id\": 3, \"parent\": 0, \"character\": \"b\", \"terminal\": true}]",
"query": "ac"
},
"output": {
"result": {
"witness": {
"position": 1,
"character": "c",
"prefix": "a"
}
}
}
}Limitations and assumptions
- A null missing-edge witness does not prove terminal-word membership.
- Ordinary node tables have at most 128 nodes with distinct IDs 0–127, one root ID 0 with empty character and null parent, unique parent/character edges, complete acyclic parent links and a boolean terminal flag. Every nonroot character is exactly one UTF-16 code unit.
- Every declared outer field is required and unknown outer fields are rejected. Strings and JSON text have size limits, lists are bounded to 128 entries, and JSON nesting/node counts are bounded. Tighter operation-specific bounds stated above take precedence.
- Ordinary numeric outputs must be finite and within safe-integer magnitude. Exact large lengths/counts use decimal strings. Original record indexes and code-unit positions are zero-based; span ends are exclusive unless stated otherwise.
Alternative or Complementary methods
Choose word membership, prefix existence, completion or ranking according to the question. Normalize text separately if needed; these operations preserve exact code units and caller order.
References
Similar or alternative tools
- Prefix Trie Compressed Edge Node Expander
Expand an explicit compressed rooted trie edge table into stable insertion-code-unit nodes, validating complete unique-parent acyclic structure and unambiguous outgoing first characters; IDs are reallocated, not preserved.
- Prefix Trie Path Compressed Edge Table
Bounded explicit prefix trie with root ID 0, unique sibling UTF-16 code-unit edges and terminal flags; compress unary nonterminal chains to multi-code-unit edge labels while retaining source endpoint IDs and all terminal boundaries.