day 4: part 2: rust

2024/days/04/part2/Cargo.toml

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+[package]
+name = "part1"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

2024/days/04/part2/src/main.rs

@@ -0,0 +1,38 @@
+fn count_xmas(hay: Vec<Vec<char>>) -> u64 {
+    let mut count: u64 = 0;
+    let target: Vec<char> = vec!['M', 'A', 'S'];
+    for center_i in 1..(hay.len() - 1) {
+        for center_j in 1..(hay.len() - 1) {
+            let mut diag1: Vec<char> = Vec::new();
+            let mut diag2: Vec<char> = Vec::new();
+            for shift in 0..3 {
+                let shift: isize = shift as isize - 1;
+                diag1.push(hay[(center_i as isize + shift) as usize][(center_j as isize - shift) as usize]);
+                diag2.push(hay[(center_i as isize + shift) as usize][(center_j as isize + shift) as usize]);
+            }
+            let mut diag1_rev = diag1.clone();
+            let mut diag2_rev = diag2.clone();
+            diag1_rev.reverse();
+            diag2_rev.reverse();
+            if (diag1_rev == target || diag1 == target) && (diag2_rev == target || diag2 == target) {
+                count += 1;
+            }
+        }
+    }
+    count
+}
+
+fn main() -> std::io::Result<()> {
+    let mut hay: Vec<Vec<char>> = Vec::new();
+    for line in std::io::stdin().lines() {
+        let line = line.unwrap();
+        let mut row: Vec<char> = Vec::new();
+        for chr in line.chars() {
+            row.push(chr);
+        }
+        hay.push(row);
+    }
+    let c = count_xmas(hay);
+    println!("{}", c);
+    Ok(())
+}