adding largest-series-product

config.json

@@ -241,6 +241,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "largest-series-product",
+        "name": "Largest Series Product",
+        "uuid": "bd8035be-13a9-43c6-a535-55a54176b08d",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "allergies",
         "name": "Allergies",

exercises/practice/largest-series-product/.docs/instructions.md

@@ -0,0 +1,18 @@
+# Instructions
+
+Given a string of digits, calculate the largest product for a contiguous
+substring of digits of length n.
+
+For example, for the input `'1027839564'`, the largest product for a
+series of 3 digits is 270 (9 \* 5 \* 6), and the largest product for a
+series of 5 digits is 7560 (7 \* 8 \* 3 \* 9 \* 5).
+
+Note that these series are only required to occupy *adjacent positions*
+in the input; the digits need not be *numerically consecutive*.
+
+For the input `'73167176531330624919225119674426574742355349194934'`,
+the largest product for a series of 6 digits is 23520.
+
+For a series of zero digits, the largest product is 1 because 1 is the multiplicative identity.
+(You don't need to know what a multiplicative identity is to solve this problem;
+it just means that multiplying a number by 1 gives you the same number.)

exercises/practice/largest-series-product/.meta/config.json

@@ -0,0 +1,26 @@
+{
+  "authors": [
+    "kapitaali"
+  ],
+  "files": {
+    "solution": [
+      "src/largest-series-product.cob"
+    ],
+    "test": [
+      "tst/largest-series-product/largest-series-product.cut"
+    ],
+    "example": [
+      ".meta/proof.ci.cob"
+    ],
+    "invalidator": [
+      "test.ps1",
+      "test.sh",
+      "bin/fetch-cobolcheck",
+      "bin/fetch-cobolcheck.ps1",
+      "config.properties"
+    ]
+  },
+  "blurb": "Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.",
+  "source": "A variation on Problem 8 at Project Euler",
+  "source_url": "http://projecteuler.net/problem=8"
+}

exercises/practice/largest-series-product/.meta/proof.ci.cob

@@ -0,0 +1,73 @@
+       IDENTIFICATION DIVISION.
+       PROGRAM-ID. LARGEST-SERIES-PRODUCT.
+       AUTHOR. kapitaali.
+       ENVIRONMENT DIVISION.
+       DATA DIVISION.
+       WORKING-STORAGE SECTION.
+       01 WS-INPUTVARS.
+           05 WS-SPAN              PIC S999.
+           05 WS-DIGITS            PIC X(60).
+       01 WS-OUTPUTVARS.
+           05 WS-RESULT            PIC 9(9).
+           05 WS-ERROR             PIC X(40).
+
+       01 MY-WORKVARS.
+           05 X                    PIC 9.
+           05 A                    PIC 9999.
+           05 B                    PIC 9(9).
+           05 D                    PIC 9999.
+           05 C-LEN                PIC 9999.
+           05 STR                  PIC 9(9).
+
+       PROCEDURE DIVISION.
+
+
+       CHECK-FOR-CHARS.
+           IF WS-DIGITS IS NOT NUMERIC 
+              MOVE "digits input must only contain digits" TO WS-ERROR
+              EXIT PROGRAM 
+           END-IF.
+
+
+       COUNT-PRODUCT.
+           MOVE 0 TO WS-RESULT. 
+           COMPUTE C-LEN = C-LEN - WS-SPAN + 1.
+           PERFORM VARYING A FROM 1 BY 1 UNTIL A > C-LEN
+              MOVE FUNCTION NUMVAL(WS-DIGITS(A:WS-SPAN)) TO STR
+              MOVE FUNCTION REVERSE(STR) TO STR
+              MOVE 1 TO B
+              PERFORM VARYING D FROM 1 BY 1 UNTIL D > WS-SPAN
+                 MOVE STR(D:1) TO X
+                 COMPUTE B = B * X
+              END-PERFORM
+              IF B > WS-RESULT 
+                 MOVE B TO WS-RESULT 
+              END-IF
+           END-PERFORM.
+
+
+       LARGEST-PRODUCT.
+           PERFORM CHECK-FOR-CHARS.
+           MOVE FUNCTION LENGTH(FUNCTION TRIM(WS-DIGITS TRAILING)) 
+              TO C-LEN.
+           MOVE 1 TO WS-RESULT. 
+           EVALUATE WS-SPAN   
+              WHEN > C-LEN
+                 MOVE "span must be smaller than string length" 
+                    TO WS-ERROR
+              WHEN < 0
+                 MOVE "span must not be negative" TO WS-ERROR
+              WHEN 0 
+                 MOVE 1 TO WS-RESULT
+              WHEN = C-LEN
+                 MOVE 1 TO B
+                 MOVE FUNCTION NUMVAL(WS-DIGITS) TO STR
+                 MOVE FUNCTION REVERSE(STR) TO STR
+                 PERFORM VARYING D FROM 1 BY 1 UNTIL D > WS-SPAN
+                    MOVE STR(D:1) TO X
+                    COMPUTE B = B * X
+                 END-PERFORM
+                 MOVE B TO WS-RESULT 
+              WHEN OTHER
+                 PERFORM COUNT-PRODUCT
+           END-EVALUATE.

exercises/practice/largest-series-product/bin/fetch-cobolcheck

@@ -0,0 +1,63 @@
+#!/usr/bin/env bash
+
+# This file is a copy of the
+# https://github.com/exercism/configlet/blob/main/scripts/fetch-configlet file.
+# Please submit bugfixes/improvements to the above file to ensure that all tracks benefit from the changes.
+
+# set -eo pipefail
+
+readonly LATEST='https://api.github.com/repos/0xE282B0/cobol-check/releases/latest'
+
+case "$(uname)" in
+  Darwin*)   os='mac'     ;;
+  Linux*)    os='linux'   ;;
+  Windows*)  os='windows' ;;
+  MINGW*)    os='windows' ;;
+  MSYS_NT-*) os='windows' ;;
+  *)         os='linux'   ;;
+esac
+
+case "${os}" in
+  windows*) ext='.exe' ;;
+  *)        ext='' ;;
+esac
+
+arch="$(uname -m)"
+
+curlopts=(
+  --silent
+  --show-error
+  --fail
+  --location
+  --retry 3
+)
+
+if [[ -n "${GITHUB_TOKEN}" ]]; then
+  curlopts+=(--header "authorization: Bearer ${GITHUB_TOKEN}")
+fi
+
+suffix="${os}-${arch}${ext}"
+
+get_download_url() {
+  curl "${curlopts[@]}" --header 'Accept: application/vnd.github.v3+json' "${LATEST}" |
+    grep "\"browser_download_url\": \".*/download/.*/cobol-check.*${suffix}\"$" |
+    cut -d'"' -f4
+}
+
+main() {
+  if [[ -d ./bin ]]; then
+    output_dir="./bin"
+  elif [[ $PWD == */bin ]]; then
+    output_dir="$PWD"
+  else
+    echo "Error: no ./bin directory found. This script should be ran from a repo root." >&2
+    return 1
+  fi
+
+  output_path="${output_dir}/cobolcheck${ext}"
+  download_url="$(get_download_url)"
+  curl "${curlopts[@]}" --output "${output_path}" "${download_url}"
+  chmod +x "${output_path}"
+}
+
+main

exercises/practice/largest-series-product/bin/fetch-cobolcheck.ps1

@@ -0,0 +1,28 @@
+# This file is a copy of the
+# https://github.com/exercism/configlet/blob/main/scripts/fetch-configlet.ps1 file.
+# Please submit bugfixes/improvements to the above file to ensure that all tracks
+# benefit from the changes.
+
+$ErrorActionPreference = "Stop"
+$ProgressPreference = "SilentlyContinue"
+
+$requestOpts = @{
+    Headers           = If ($env:GITHUB_TOKEN) { @{ Authorization = "Bearer ${env:GITHUB_TOKEN}" } } Else { @{ } }
+    MaximumRetryCount = 3
+    RetryIntervalSec  = 1
+}
+
+$arch = If ([Environment]::Is64BitOperatingSystem) { "amd64" } Else { "x86" }
+$fileName = "cobol-check-windows-$arch.exe"
+
+Function Get-DownloadUrl {
+    $latestUrl = "https://api.github.com/repos/0xE282B0/cobol-check/releases/latest"
+    Invoke-RestMethod -Uri $latestUrl -PreserveAuthorizationOnRedirect @requestOpts
+    | Select-Object -ExpandProperty assets
+    | Where-Object { $_.browser_download_url -match $FileName }
+    | Select-Object -ExpandProperty browser_download_url
+}
+
+$downloadUrl = Get-DownloadUrl
+$outputFile = Join-Path -Path $PSScriptRoot -ChildPath "cobolcheck.exe"
+Invoke-WebRequest -Uri $downloadUrl -OutFile $outputFile @requestOpts