day13 part 2 brute force

2020/day13/inputPart2.txt

@@ -0,0 +1,68 @@
+19
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+37
+0
+0
+0
+0
+0
+383
+0
+0
+0
+0
+0
+0
+0
+23
+0
+0
+0
+0
+13
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+29
+0
+457
+0
+0
+0
+0
+0
+0
+0
+0
+0
+41
+0
+0
+0
+0
+0
+0
+17

2020/day13/inputPart2Test1.txt

@@ -0,0 +1,4 @@
+17
+0
+13
+19

2020/day13/inputPart2Test2.txt

@@ -0,0 +1,5 @@
+67
+7
+0
+59
+61

2020/day13/inputPart2Test3.txt

@@ -0,0 +1,5 @@
+67
+7
+0
+59
+61

2020/day13/mainPart2.zig

@@ -0,0 +1,62 @@
+const input = @embedFile("inputPart2.txt");
+const std = @import("std");
+
+
+pub fn main() !void {
+
+    //Data wrangling
+    var it = std.mem.tokenize(u8, input, "\n");
+    var busses:[68]u32 = std.mem.zeroes([68:0]u32);
+    var i: u32 = 0;
+
+    while(it.next())
+        |line|
+        :(i+=1)
+    {
+        busses[i] = readNum(line);
+    }
+
+    //count total active buslines
+    var busTotal: u8 = 0;
+    for(busses)|bus|{
+        if(bus > 0)
+            busTotal += 1;
+    }
+
+    const stepSize: u32 = 1;
+    var n: u64 = 1;
+    var found: u8 = 0;
+
+    //Algorithm
+    while(found != busTotal):(n+=stepSize){
+        
+        for(busses, 0..)|bus, offset|{
+            //skip
+            if(bus == 0){
+                continue;
+            }
+
+            if(((n + offset) % bus) == 0){
+                found +=1;
+            }
+        }
+
+        if(found >= 7){
+            std.debug.print("tick {d} has {d} aligned!\n",.{n, found});
+        }
+
+        if(found == busTotal){
+            std.debug.print("Final tick {d}\n",.{n});
+            break;
+        }else{
+            found = 0;
+        }
+    }
+}
+
+fn readNum(line: []const u8) u32 {
+    return std.fmt.parseInt(u32, line, 10) catch {
+        return 0;
+    };
+
+}