# Array integer adjacent diff

`array-integer-adjacent-diff` · version 1.0.0 · Numbers & math · free, no key needed

Replace an array of canonical integer strings with consecutive first differences.

**Use when you need to: array integer adjacent diff · consecutive integer differences · first differences of integer array.**

## Supported

- array integer adjacent diff
- consecutive integer differences
- first differences of integer array

## Not supported

- second differences
- percentage change
- floating point differences
- derivative of a function
- CSV column differences

## Behavior

- Input values is an array of at most 10000 canonical integer strings.
- A canonical integer is 0 or an optional ASCII minus followed by a non-zero leading digit and only digits after that.
- Input -0 is accepted and canonicalized to 0; +, spaces, underscores, hex, exponents, empty strings, and other leading zeros are rejected.
- Integers are parsed with BigInt. IEEE-754 numbers are rejected.
- Output values has length n-1; item i is values[i+1] minus values[i] as a canonical integer string.
- Arrays of length 0 or 1 yield an empty array.
- Each input and every difference may have at most 1000 digits excluding the sign.

## Input

- `values` (array of string, required): max items 10000; each min length 1; each max length 1001

## Output

- `values` (array of string, required): max items 9999; each max length 1001; each pattern `^(0|-?[1-9][0-9]*)$`

## Limits

- max items: 10000
- max digits: 1000

## Example

Request input:

```json
{
  "values": [
    "4",
    "-1",
    "7",
    "0"
  ]
}
```

Response:

```json
{
  "result": {
    "values": [
      "-5",
      "8",
      "-7"
    ]
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "array-integer-adjacent-diff",
  "version": "1.0.0",
  "input": {
    "values": [
      "4",
      "-1",
      "7",
      "0"
    ]
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/array-integer-adjacent-diff/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"values":["4","-1","7","0"]}'
```

The machine-readable contract is at [/v1/tools/array-integer-adjacent-diff/versions/1.0.0](/v1/tools/array-integer-adjacent-diff/versions/1.0.0).

### CLI

```sh
node cli.mjs run array-integer-adjacent-diff 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Array integer cumulative sum](/tools/array-integer-cumulative-sum): Replace an array of canonical integer strings with equal-length prefix sums.
- [Array integer GCD](/tools/array-integer-gcd): Compute the non-negative greatest common divisor of an array of canonical integer strings.
- [Array integer LCM](/tools/array-integer-lcm): Compute the non-negative least common multiple of an array of canonical integer strings.
- [Array integer median](/tools/array-integer-median): Select lower and upper middle canonical integers; emit median only for odd length.
- [Array integer min max](/tools/array-integer-min-max): Return the numeric minimum and maximum of canonical integer strings.
- [Array integer mode](/tools/array-integer-mode): Return the most frequent canonical integers, listing every mode in first-seen order.