Day 17

AoC21.xcodeproj/project.pbxproj

@@ -19,6 +19,8 @@
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 		263CCF79276606730061B353 /* common.swift in Sources */ = {isa = PBXBuildFile; fileRef = 269BE5CB2762A08800871C85 /* common.swift */; };
+		263D3E33276DDA6600B0AC5B /* day17.swift in Sources */ = {isa = PBXBuildFile; fileRef = 263D3E32276DDA6600B0AC5B /* day17.swift */; };
+		263D3E34276DDA7000B0AC5B /* common.swift in Sources */ = {isa = PBXBuildFile; fileRef = 269BE5CB2762A08800871C85 /* common.swift */; };
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@@ -95,6 +97,15 @@
 			);
 			runOnlyForDeploymentPostprocessing = 1;
 		};
+		263D3E29276DDA5400B0AC5B /* CopyFiles */ = {
+			isa = PBXCopyFilesBuildPhase;
+			buildActionMask = 2147483647;
+			dstPath = /usr/share/man/man1/;
+			dstSubfolderSpec = 0;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 1;
+		};
 		2651128D2767D15A009B7607 /* CopyFiles */ = {
 			isa = PBXCopyFilesBuildPhase;
 			buildActionMask = 2147483647;
@@ -148,6 +159,8 @@
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 		263CCF6F2766065B0061B353 /* Day12 */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = Day12; sourceTree = BUILT_PRODUCTS_DIR; };
 		263CCF76276606670061B353 /* day12.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = day12.swift; sourceTree = "<group>"; };
+		263D3E2B276DDA5400B0AC5B /* Day17 */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = Day17; sourceTree = BUILT_PRODUCTS_DIR; };
+		263D3E32276DDA6600B0AC5B /* day17.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = day17.swift; sourceTree = "<group>"; };
 		2651128F2767D15A009B7607 /* Day13 */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = Day13; sourceTree = BUILT_PRODUCTS_DIR; };
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@@ -209,6 +222,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		263D3E28276DDA5400B0AC5B /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 		2651128C2767D15A009B7607 /* Frameworks */ = {
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
@@ -243,6 +263,7 @@
 		263BA594275E974800839C92 = {
 			isa = PBXGroup;
 			children = (
+				263D3E32276DDA6600B0AC5B /* day17.swift */,
 				26EA5DFF276BA680003E0305 /* day16.swift */,
 				26155467276A6D0A00374D18 /* day15.swift */,
 				26155459276A6C2C00374D18 /* day14.swift */,
@@ -273,6 +294,7 @@
 				26155452276A6C1C00374D18 /* Day14 */,
 				26155460276A6CF700374D18 /* Day15 */,
 				26EA5DF7276BA668003E0305 /* Day16 */,
+				263D3E2B276DDA5400B0AC5B /* Day17 */,
 			);
 			name = Products;
 			sourceTree = "<group>";
@@ -399,6 +421,23 @@
 			productReference = 263CCF6F2766065B0061B353 /* Day12 */;
 			productType = "com.apple.product-type.tool";
 		};
+		263D3E2A276DDA5400B0AC5B /* Day17 */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = 263D3E31276DDA5400B0AC5B /* Build configuration list for PBXNativeTarget "Day17" */;
+			buildPhases = (
+				263D3E27276DDA5400B0AC5B /* Sources */,
+				263D3E28276DDA5400B0AC5B /* Frameworks */,
+				263D3E29276DDA5400B0AC5B /* CopyFiles */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = Day17;
+			productName = Day17;
+			productReference = 263D3E2B276DDA5400B0AC5B /* Day17 */;
+			productType = "com.apple.product-type.tool";
+		};
 		2651128E2767D15A009B7607 /* Day13 */ = {
 			isa = PBXNativeTarget;
 			buildConfigurationList = 265112952767D15A009B7607 /* Build configuration list for PBXNativeTarget "Day13" */;
@@ -504,6 +543,10 @@
 					263CCF6E2766065B0061B353 = {
 						CreatedOnToolsVersion = 13.1;
 					};
+					263D3E2A276DDA5400B0AC5B = {
+						CreatedOnToolsVersion = 13.2;
+						LastSwiftMigration = 1320;
+					};
 					2651128E2767D15A009B7607 = {
 						CreatedOnToolsVersion = 13.1;
 						LastSwiftMigration = 1310;
@@ -544,6 +587,7 @@
 				26155451276A6C1C00374D18 /* Day14 */,
 				2615545F276A6CF700374D18 /* Day15 */,
 				26EA5DF6276BA668003E0305 /* Day16 */,
+				263D3E2A276DDA5400B0AC5B /* Day17 */,
 			);
 		};
 /* End PBXProject section */
@@ -612,6 +656,15 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
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+			buildActionMask = 2147483647;
+			files = (
+				263D3E34276DDA7000B0AC5B /* common.swift in Sources */,
+				263D3E33276DDA6600B0AC5B /* day17.swift in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
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 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
@@ -985,6 +1038,43 @@
 			};
 			name = Release;
 		};
+		263D3E2F276DDA5400B0AC5B /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = 722B335UM5;
+				ENABLE_HARDENED_RUNTIME = YES;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/../Frameworks",
+					"@loader_path/../Frameworks",
+				);
+				MACOSX_DEPLOYMENT_TARGET = 12.1;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 5.0;
+			};
+			name = Debug;
+		};
+		263D3E30276DDA5400B0AC5B /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = 722B335UM5;
+				ENABLE_HARDENED_RUNTIME = YES;
+				LD_RUNPATH_SEARCH_PATHS = (
+					"$(inherited)",
+					"@executable_path/../Frameworks",
+					"@loader_path/../Frameworks",
+				);
+				MACOSX_DEPLOYMENT_TARGET = 12.1;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 5.0;
+			};
+			name = Release;
+		};
 		265112932767D15A009B7607 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
@@ -1176,6 +1266,15 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
+		263D3E31276DDA5400B0AC5B /* Build configuration list for PBXNativeTarget "Day17" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				263D3E2F276DDA5400B0AC5B /* Debug */,
+				263D3E30276DDA5400B0AC5B /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
 		265112952767D15A009B7607 /* Build configuration list for PBXNativeTarget "Day13" */ = {
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day17.swift

@@ -0,0 +1,71 @@
+@main
+struct Day17: Puzzle {
+    func run() {
+        var maxHeight: Int = 0
+        var count = 0
+
+        for speedX in 1..<300 {
+            for speedY in -600..<300 {
+                if case .hit(let height) = run(vx: speedX, vy: speedY) {
+                    maxHeight = max(height, maxHeight)
+                    count += 1
+                }
+            }
+        }
+
+        print("Part 1:", maxHeight)
+        print("Part 2:", count)
+    }
+
+    enum Result {
+        case tooFar
+        case tooShort
+        case hit(height: Int)
+    }
+
+    struct Vector: Hashable {
+        var x: Int
+        var y: Int
+    }
+
+    func run(vx: Int, vy: Int) -> Result {
+        var state = State(vx: vx, vy: vy)
+        while state.x <= xMax && state.y >= yMin {
+            state.step()
+            if xMin...xMax ~= state.x && yMin...yMax ~=  state.y {
+                return .hit(height: state.maxHeight)
+            }
+        }
+
+        if state.x > xMax {
+            return .tooFar
+        }
+
+        return .tooShort
+    }
+
+    struct State {
+        var vx: Int
+        var vy: Int
+        var x: Int = 0
+        var y: Int = 0
+        var maxHeight = 0
+
+        mutating func step() {
+            if y > maxHeight {
+                maxHeight = y
+            }
+
+            x += vx
+            y += vy
+            vx -= vx.signum()
+            vy -= 1
+        }
+    }
+
+    // target area: x=138..184, y=-125..-71
+    let xMin = 138
+    let xMax = 184
+    let yMin = -125
+    let yMax = -71
+}