past202010-open g

cargo-atcoder-1.70.0/contests/past202010-open/src/bin/g.rs

@@ -1,10 +1,63 @@
-use proconio::{input, marker::Usize1};
+use std::collections::VecDeque;
+
+use proconio::{input, marker::Chars};
+
+fn ok(n: usize, m: usize, s: &[Vec<char>]) -> bool {
+    let mut count = 0_usize;
+    let mut visited = vec![vec![false; m]; n];
+    for i in 0..n {
+        for j in 0..m {
+            if s[i][j] == '#' || visited[i][j] {
+                continue;
+            }
+
+            count += 1;
+            let mut deque = VecDeque::new();
+            visited[i][j] = true;
+            deque.push_back((i, j));
+            while let Some((r, c)) = deque.pop_front() {
+                let dir = vec![(-1, 0), (0, -1), (0, 1), (1, 0)];
+                for (dr, dc) in dir {
+                    let (nr, nc) = (r as i64 + dr, c as i64 + dc);
+                    if !(0..n as i64).contains(&nr) || !(0..m as i64).contains(&nc) {
+                        continue;
+                    }
+                    let (nr, nc) = (nr as usize, nc as usize);
+                    if s[nr][nc] == '#' {
+                        continue;
+                    }
+                    if visited[nr][nc] {
+                        continue;
+                    }
+                    visited[nr][nc] = true;
+                    deque.push_back((nr, nc));
+                }
+            }
+        }
+    }
+    count == 1
+}
 
 fn main() {
     input! {
         n: usize,
-        a: [Usize1; n],
+        m: usize,
+        mut s: [Chars; n],
     };
-    let ans = n - a.len();
+
+    let mut count = 0_usize;
+    for i in 0..n {
+        for j in 0..m {
+            if s[i][j] != '#' {
+                continue;
+            }
+            s[i][j] = '.';
+            if ok(n, m, &s) {
+                count += 1;
+            }
+            s[i][j] = '#';
+        }
+    }
+    let ans = count;
     println!("{}", ans);
 }