new exercise: saddle-points

config.json

@@ -685,6 +685,14 @@
         "uuid": "9edd0fda-cc73-40a2-a32c-b16918c65167",
         "practices": [],
         "prerequisites": [],
+        "difficulty": 2
+      },
+      {
+        "slug": "saddle-points",
+        "name": "Saddle Points",
+        "uuid": "5efb23b7-fa38-4667-a344-4455877beb03",
+        "practices": [],
+        "prerequisites": [],
         "difficulty": 4
       }
     ]

exercises/practice/saddle-points/.docs/instructions.append.md

@@ -0,0 +1,18 @@
+## Input format
+
+The input will be in the format of a string. To keep this exercise beginner-friendly, you need not expect numbers with multiple digits.
+
+Bytes 64-191 of the linear memory are reserved for the input string.
+
+## Output format
+
+The output is expected in pairs of row and column as u8 directly concatenated.
+
+For example, if there are three saddle points
+
+row: 2, column: 1
+row: 2, column: 2
+row: 2, column: 3
+
+then the expected output would be the u8 values `2, 1, 2, 2, 2, 3`
+

exercises/practice/saddle-points/.docs/instructions.md

@@ -0,0 +1,27 @@
+# Instructions
+
+Your task is to find the potential trees where you could build your tree house.
+
+The data company provides the data as grids that show the heights of the trees.
+The rows of the grid represent the east-west direction, and the columns represent the north-south direction.
+
+An acceptable tree will be the largest in its row, while being the smallest in its column.
+
+A grid might not have any good trees at all.
+Or it might have one, or even several.
+
+Here is a grid that has exactly one candidate tree.
+
+```text
+      ↓
+      1  2  3  4
+    |-----------
+  1 | 9  8  7  8
+→ 2 |[5] 3  2  4
+  3 | 6  6  7  1
+```
+
+- Row 2 has values 5, 3, 2, and 4. The largest value is 5.
+- Column 1 has values 9, 5, and 6. The smallest value is 5.
+
+So the point at `[2, 1]` (row: 2, column: 1) is a great spot for a tree house.

exercises/practice/saddle-points/.docs/introduction.md

@@ -0,0 +1,11 @@
+# Introduction
+
+You plan to build a tree house in the woods near your house so that you can watch the sun rise and set.
+
+You've obtained data from a local survey company that show the height of every tree in each rectangular section of the map.
+You need to analyze each grid on the map to find good trees for your tree house.
+
+A good tree is both:
+
+- taller than every tree to the east and west, so that you have the best possible view of the sunrises and sunsets.
+- shorter than every tree to the north and south, to minimize the amount of tree climbing.

exercises/practice/saddle-points/.eslintrc

@@ -0,0 +1,18 @@
+{
+  "root": true,
+  "extends": "@exercism/eslint-config-javascript",
+  "env": {
+    "jest": true
+  },
+  "overrides": [
+    {
+      "files": [
+        "*.spec.js"
+      ],
+      "excludedFiles": [
+        "custom.spec.js"
+      ],
+      "extends": "@exercism/eslint-config-javascript/maintainers"
+    }
+  ]
+}

exercises/practice/saddle-points/.meta/config.json

@@ -0,0 +1,29 @@
+{
+  "authors": [
+    "atk"
+  ],
+  "files": {
+    "solution": [
+      "saddle-points.wat"
+    ],
+    "test": [
+      "saddle-points.spec.js"
+    ],
+    "example": [
+      ".meta/proof.ci.wat"
+    ],
+    "invalidator": [
+      "package.json"
+    ]
+
+  },
+  "blurb": "Detect saddle points in a matrix.",
+  "source": "J Dalbey's Programming Practice problems",
+  "source_url": "https://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html",
+  "custom": {
+    "version.tests.compatibility": "jest-27",
+    "flag.tests.task-per-describe": false,
+    "flag.tests.may-run-long": false,
+    "flag.tests.includes-optional": false
+  }
+}

exercises/practice/saddle-points/.meta/proof.ci.wat

@@ -0,0 +1,71 @@
+(module
+  (memory (export "mem") 1)
+
+  (global $outputOffset i32 (i32.const 1280))
+  (global $parsedOffset i32 (i32.const 512))
+  (global $rowMaxOffset i32 (i32.const 768))
+  (global $colMinOffset i32 (i32.const 1024))
+  (global $zero i32 (i32.const 48))
+  (global $br i32 (i32.const 10))
+
+  ;;
+  ;; Find the points in the matrix that are the largest in row and smallest in column
+  ;;
+  ;; @param {i32} $inputOffset - offset of the matrix in linear memory
+  ;; @param {i32} $inputLength - length of the matrix in linear memory
+  ;;
+  ;; @result {(i32,i32)} - offset and length of row-column-pairs in linear memory
+  ;;
+  (func (export "saddlePoints") (param $inputOffset i32) (param $inputLength i32) (result i32 i32)
+    (local $row i32)
+    (local $column i32)
+    (local $lineLength i32)
+    (local $rowsLength i32)
+    (local $char i32)
+    (local $pos i32)
+    (local $height i32)
+    (local $outputLength i32)
+    (if (i32.eqz (local.get $inputLength)) (then (return (global.get $outputOffset) (i32.const 0))))
+    (loop $scanInput
+      (local.set $char (i32.load8_u (i32.add (local.get $inputOffset) (local.get $pos))))
+      (if (i32.ge_u (local.get $char) (global.get $zero))
+      (then (local.set $height (i32.add (i32.mul (local.get $height) (i32.const 10))
+        (i32.sub (local.get $char) (global.get $zero)))))
+      (else (i32.store8 (i32.add (global.get $parsedOffset) (local.get $outputLength)) (local.get $height))
+        (local.set $outputLength (i32.add (local.get $outputLength) (i32.const 1))
+        (if (i32.gt_u (local.get $height) (i32.load8_u (i32.add (global.get $rowMaxOffset) (local.get $row))))
+          (then (i32.store8 (i32.add (global.get $rowMaxOffset) (local.get $row)) (local.get $height))))
+        (if (i32.le_u (local.get $height) (i32.sub (i32.load8_u (i32.add (global.get $colMinOffset)
+          (local.get $column))) (i32.const 1)))
+          (then (i32.store8 (i32.add (global.get $colMinOffset) (local.get $column)) (local.get $height))))
+        (local.set $column (i32.add (local.get $column) (i32.const 1)))
+        (local.set $height (i32.const 0)))))
+      (if (i32.eq (local.get $char) (global.get $br)) (then
+        (if (i32.eqz (local.get $lineLength)) (then (local.set $lineLength (local.get $pos))))
+        (local.set $row (i32.add (local.get $row) (i32.const 1))
+        (local.set $column (i32.const 0)))))
+      (local.set $pos (i32.add (local.get $pos) (i32.const 1)))
+    (br_if $scanInput (i32.lt_u (local.get $pos) (local.get $inputLength))))
+    (local.set $rowsLength (local.get $row))
+    (local.set $lineLength (i32.div_u (local.get $outputLength) (local.get $rowsLength)))
+    (local.set $outputLength (i32.const 0))
+    (local.set $row (i32.const 0))
+    (loop $rows
+      (local.set $column (i32.const 0))
+      (loop $columns
+        (local.set $height (i32.load8_u (i32.add (global.get $parsedOffset)
+          (i32.add (i32.mul (local.get $row) (local.get $lineLength)) (local.get $column)))))
+        (if (i32.and (i32.eq (local.get $height)
+          (i32.load8_u (i32.add (global.get $rowMaxOffset) (local.get $row))))
+          (i32.eq (local.get $height) (i32.load8_u (i32.add (global.get $colMinOffset) (local.get $column)))))
+          (then (i32.store16 (i32.add (global.get $outputOffset) (local.get $outputLength))
+              (i32.or (i32.shl (i32.add (local.get $column) (i32.const 1)) (i32.const 8))
+                (i32.add (local.get $row) (i32.const 1))))
+            (local.set $outputLength (i32.add (local.get $outputLength) (i32.const 2)))))
+        (local.set $column (i32.add (local.get $column) (i32.const 1)))
+      (br_if $columns (i32.lt_u (local.get $column) (local.get $lineLength))))
+      (local.set $row (i32.add (local.get $row) (i32.const 1)))
+    (br_if $rows (i32.lt_u (local.get $row) (local.get $rowsLength))))
+    (global.get $outputOffset) (local.get $outputLength)
+  )
+)

exercises/practice/saddle-points/.meta/tests.toml

@@ -0,0 +1,37 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[3e374e63-a2e0-4530-a39a-d53c560382bd]
+description = "Can identify single saddle point"
+
+[6b501e2b-6c1f-491f-b1bb-7f278f760534]
+description = "Can identify that empty matrix has no saddle points"
+
+[8c27cc64-e573-4fcb-a099-f0ae863fb02f]
+description = "Can identify lack of saddle points when there are none"
+
+[6d1399bd-e105-40fd-a2c9-c6609507d7a3]
+description = "Can identify multiple saddle points in a column"
+
+[3e81dce9-53b3-44e6-bf26-e328885fd5d1]
+description = "Can identify multiple saddle points in a row"
+
+[88868621-b6f4-4837-bb8b-3fad8b25d46b]
+description = "Can identify saddle point in bottom right corner"
+
+[5b9499ca-fcea-4195-830a-9c4584a0ee79]
+description = "Can identify saddle points in a non square matrix"
+
+[ee99ccd2-a1f1-4283-ad39-f8c70f0cf594]
+description = "Can identify that saddle points in a single column matrix are those with the minimum value"
+
+[63abf709-a84b-407f-a1b3-456638689713]
+description = "Can identify that saddle points in a single row matrix are those with the maximum value"

exercises/practice/saddle-points/.npmrc

@@ -0,0 +1 @@
+audit=false

exercises/practice/saddle-points/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Exercism
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

exercises/practice/saddle-points/babel.config.js

@@ -0,0 +1,4 @@
+export default {
+  presets: ["@exercism/babel-preset-javascript"],
+  plugins: [],
+};

exercises/practice/saddle-points/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "@exercism/wasm-saddle-points",
+  "description": "Exercism exercises in WebAssembly.",
+  "author": "Alex Lohr",
+  "type": "module",
+  "private": true,
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/exercism/wasm",
+    "directory": "exercises/practice/saddle-points"
+  },
+  "jest": {
+    "maxWorkers": 1
+  },
+  "devDependencies": {
+    "@babel/core": "^7.23.3",
+    "@exercism/babel-preset-javascript": "^0.4.0",
+    "@exercism/eslint-config-javascript": "^0.6.0",
+    "@types/jest": "^29.5.8",
+    "@types/node": "^20.9.1",
+    "babel-jest": "^29.7.0",
+    "core-js": "^3.33.2",
+    "eslint": "^8.54.0",
+    "jest": "^29.7.0"
+  },
+  "dependencies": {
+    "@exercism/wasm-lib": "^0.2.0"
+  },
+  "scripts": {
+    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js ./*",
+    "watch": "node --experimental-vm-modules node_modules/jest/bin/jest.js --watch ./*",
+    "lint": "eslint ."
+  }
+}