2022 Day 10 part 1

2022/day10.m

@@ -0,0 +1,73 @@
+// clang day10.m -fmodules -o day10 && ./day10
+
+@import Foundation;
+
+@interface CPUState: NSObject
+
+@property (readonly, nonatomic) int signalSum;
+
+- (void)noop;
+- (void)addX: (int)value;
+
+@end
+
+@implementation CPUState {
+    int x;
+    int counter;
+    int *nextSample;
+}
+
+static int samplePositions[] = {20, 60, 100, 140, 180, 220, -1};
+
+- init;
+{
+    self = [super init];
+    x = 1;
+    counter = 0;
+    nextSample = samplePositions;
+    _signalSum = 0;
+    return self;
+}
+
+- (void)step;
+{
+    counter++;
+    if (counter == *nextSample) {
+        _signalSum += counter * x;
+        ++nextSample;
+    }
+}
+
+- (void)noop;
+{
+    [self step];
+}
+
+- (void)addX: (int)value;
+{
+    [self step];
+    [self step];
+    x += value;
+}
+
+@end
+
+    
+int main() {
+    
+    NSScanner *scanner = [NSScanner scannerWithString: [NSString stringWithContentsOfFile: @"day10.input" encoding: NSUTF8StringEncoding error: NULL]];
+    
+    CPUState *state = [[CPUState alloc] init];
+    
+    while (![scanner isAtEnd]) {
+        int argument = 0;
+        if ([scanner scanString: @"noop" intoString: NULL]) {
+            [state noop];
+        } else if ([scanner scanString: @"addx" intoString: NULL] && [scanner scanInt: &argument]) {
+            [state addX: argument];
+        }
+    }
+
+    NSLog(@"Part 1: %d", state.signalSum);
+    
+}