aoc-2024/src/day_04/part_1.rs

48 lines
1.2 KiB
Rust

pub fn answer(s : &str) -> u32 {
let grid : Vec<Vec<char>> = s.split("\n")
.map(|s| s.chars().collect())
.collect();
let rows : i32 = grid.len().try_into().unwrap();
let cols : i32 = grid[0].len().try_into().unwrap();
let mut total : u32 = 0;
for y in 0..rows {
for x in 0..cols {
if grid[y as usize][x as usize] == 'X' {
total = total + inspect_location(&grid, x, y, rows, cols)
}
}
};
total
}
fn inspect_location(grid : &Vec<Vec<char>>, x : i32, y : i32, rows : i32, cols : i32) -> u32 {
let mut total = 0;
for dx in -1..=1 {
for dy in -1..=1 {
if dx == 0 && dy == 0 {
continue;
}
let (s_x, s_y) = ( x + 3 * dx, y + 3 * dy );
if s_x < 0 || s_x >= rows || s_y < 0 || s_y >= cols {
continue;
}
let m = grid[(y + 1 * dy) as usize][(x + 1 * dx) as usize];
let a = grid[(y + 2 * dy) as usize][(x + 2 * dx) as usize];
let s = grid[(y + 3 * dy) as usize][(x + 3 * dx) as usize];
if m == 'M' && a == 'A' && s == 'S' {
total = total + 1;
}
}
};
total
}