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const std = @import("std");
const stdin = std.io.getStdIn();
const print = std.debug.print;
pub fn solve(part: []u8, buffer: []u8) !void {
var lines = std.mem.splitScalar(u8, buffer, '\n');
if (std.mem.eql(u8, part, "part1")) {
try part1(&lines);
} else {
try part2(&lines);
}
}
fn part1(lines: *std.mem.SplitIterator(u8, .scalar)) !void {
var count: usize = 0;
lines: while (lines.next()) |line| {
if (line.len > 0) {
var components = std.mem.splitScalar(u8, line, ' ');
var previous: i32 = try std.fmt.parseInt(i32, components.next().?, 10);
var increasing: i32 = 0;
while (components.next()) |number_s| {
const number = try std.fmt.parseInt(i32, number_s, 10);
if (increasing == 0) {
if (previous > number) {
increasing = -1;
} else {
increasing = 1;
}
}
const difference = (number - previous) * increasing;
if (difference < 1 or difference > 3) {
continue :lines;
}
previous = number;
}
count += 1;
}
}
print("Safe count: {d}\n", .{count});
}
fn part2(lines: *std.mem.SplitIterator(u8, .scalar)) !void {
var count: usize = 0;
while (lines.next()) |line| {
if (line.len > 0) {
var components = std.mem.splitScalar(u8, line, ' ');
var i: usize = 0;
var j: usize = 0;
counter: while (i <= j) {
j = 0;
components.reset();
if (i == 0) {
_ = components.next();
}
var previous: i32 = try std.fmt.parseInt(i32, components.next().?, 10);
var increasing: i32 = 0;
while (components.next()) |number_s| {
if (i != j) {
const number = try std.fmt.parseInt(i32, number_s, 10);
if (increasing == 0) {
if (previous > number) {
increasing = -1;
} else {
increasing = 1;
}
}
const difference = (number - previous) * increasing;
if (difference < 1 or difference > 3) {
i += 1;
continue :counter;
}
previous = number;
}
j += 1;
}
count += 1;
break;
}
}
}
print("Safe count: {d}\n", .{count});
}
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