Exercise queen-attack (#358)

config.json

@@ -782,6 +782,14 @@
         "topics": [
           "integers"
         ]
+      },
+      {
+        "slug": "queen-attack",
+        "name": "Queen Attack",
+        "uuid": "8cc61958-ca54-49d5-a269-d81ee6f512f9",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
       }
     ]
   },

exercises/practice/queen-attack/.docs/instructions.md

@@ -0,0 +1,25 @@
+# Instructions
+
+Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.
+
+In the game of chess, a queen can attack pieces which are on the same row, column, or diagonal.
+
+A chessboard can be represented by an 8 by 8 array.
+
+So if you are told the white queen is at `c5` (zero-indexed at column 2, row 3) and the black queen at `f2` (zero-indexed at column 5, row 6), then you know that the set-up is like so:
+
+```text
+  a b c d e f g h
+8 _ _ _ _ _ _ _ _ 8
+7 _ _ _ _ _ _ _ _ 7
+6 _ _ _ _ _ _ _ _ 6
+5 _ _ W _ _ _ _ _ 5
+4 _ _ _ _ _ _ _ _ 4
+3 _ _ _ _ _ _ _ _ 3
+2 _ _ _ _ _ B _ _ 2
+1 _ _ _ _ _ _ _ _ 1
+  a b c d e f g h
+```
+
+You are also able to answer whether the queens can attack each other.
+In this case, that answer would be yes, they can, because both pieces share a diagonal.

exercises/practice/queen-attack/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "files": {
+    "solution": [
+      "src/main/groovy/QueenAttack.groovy"
+    ],
+    "test": [
+      "src/test/groovy/QueenAttackSpec.groovy"
+    ],
+    "example": [
+      ".meta/src/reference/groovy/QueenAttack.groovy"
+    ]
+  },
+  "blurb": "Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.",
+  "source": "J Dalbey's Programming Practice problems",
+  "source_url": "https://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html"
+}

exercises/practice/queen-attack/.meta/src/reference/groovy/Queen.groovy

@@ -0,0 +1,14 @@
+class Queen {
+    final int row
+    final int column
+
+    Queen(int row, int column) {
+        if (row < 0 || row > 7)
+            throw new Exception("invalid row")
+        if (column < 0 || column > 7)
+            throw new Exception("invalid column")
+
+        this.row = row
+        this.column = column
+    }
+}

exercises/practice/queen-attack/.meta/src/reference/groovy/QueenAttack.groovy

@@ -0,0 +1,8 @@
+class QueenAttack {
+
+    static canAttack(Queen q1, Queen q2) {
+        int rowDelta = (q1.row - q2.row).abs()
+        int columnDelta = (q1.column - q2.column).abs()
+        return rowDelta == 0 || columnDelta == 0 || rowDelta == columnDelta
+    }
+}

exercises/practice/queen-attack/.meta/tests.toml

@@ -0,0 +1,49 @@
+# 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.
+
+[3ac4f735-d36c-44c4-a3e2-316f79704203]
+description = "Test creation of Queens with valid and invalid positions -> queen with a valid position"
+
+[4e812d5d-b974-4e38-9a6b-8e0492bfa7be]
+description = "Test creation of Queens with valid and invalid positions -> queen must have positive row"
+
+[f07b7536-b66b-4f08-beb9-4d70d891d5c8]
+description = "Test creation of Queens with valid and invalid positions -> queen must have row on board"
+
+[15a10794-36d9-4907-ae6b-e5a0d4c54ebe]
+description = "Test creation of Queens with valid and invalid positions -> queen must have positive column"
+
+[6907762d-0e8a-4c38-87fb-12f2f65f0ce4]
+description = "Test creation of Queens with valid and invalid positions -> queen must have column on board"
+
+[33ae4113-d237-42ee-bac1-e1e699c0c007]
+description = "Test the ability of one queen to attack another -> cannot attack"
+
+[eaa65540-ea7c-4152-8c21-003c7a68c914]
+description = "Test the ability of one queen to attack another -> can attack on same row"
+
+[bae6f609-2c0e-4154-af71-af82b7c31cea]
+description = "Test the ability of one queen to attack another -> can attack on same column"
+
+[0e1b4139-b90d-4562-bd58-dfa04f1746c7]
+description = "Test the ability of one queen to attack another -> can attack on first diagonal"
+
+[ff9b7ed4-e4b6-401b-8d16-bc894d6d3dcd]
+description = "Test the ability of one queen to attack another -> can attack on second diagonal"
+
+[0a71e605-6e28-4cc2-aa47-d20a2e71037a]
+description = "Test the ability of one queen to attack another -> can attack on third diagonal"
+
+[0790b588-ae73-4f1f-a968-dd0b34f45f86]
+description = "Test the ability of one queen to attack another -> can attack on fourth diagonal"
+
+[543f8fd4-2597-4aad-8d77-cbdab63619f8]
+description = "Test the ability of one queen to attack another -> cannot attack if falling diagonals are only the same when reflected across the longest falling diagonal"

exercises/practice/queen-attack/.meta/version

@@ -0,0 +1 @@
+0.1.0

exercises/practice/queen-attack/build.gradle

@@ -0,0 +1,18 @@
+apply plugin: "groovy"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation "org.spockframework:spock-core:2.0-M2-groovy-3.0"
+    implementation "org.codehaus.groovy:groovy-all:3.0.2"
+}
+
+test {
+    useJUnitPlatform()
+    testLogging {
+        exceptionFormat = 'full'
+        events = ["passed", "failed", "skipped"]
+    }
+}

exercises/practice/queen-attack/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.2-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

exercises/practice/queen-attack/gradlew

@@ -0,0 +1,183 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"