20250221 finished.

src/problem/mod.rs

@@ -496,3 +496,5 @@ mod p2080_range_frequency_queries;
 mod p624_maximum_distance_in_arrays;
 
 mod p2595_number_of_even_and_odd_bits;
+
+mod p2209_minimum_white_tiles_after_covering_with_carpets;

src/problem/p2209_minimum_white_tiles_after_covering_with_carpets.rs

@@ -0,0 +1,68 @@
+use std::ffi::FromVecWithNulError;
+
+/**
+ * [2209] Minimum White Tiles After Covering With Carpets
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn minimum_white_tiles(floor: String, num_carpets: i32, carpet_len: i32) -> i32 {
+        let carpets_num = num_carpets as usize;
+        let carpet_length = carpet_len as usize;
+        let floor: Vec<bool> = floor
+            .chars()
+            .into_iter()
+            .map(|x| if x == '0' { true } else { false })
+            .collect();
+
+        // dp[i][j] 表示
+        // 当使用j块地毯时
+        // [i..] 还有多少白色的地砖没有被覆盖
+        let mut dp = vec![vec![0; carpets_num + 1]; floor.len()];
+
+        // 初始化dp[i][0]
+        let mut white_count = 0;
+        for i in (0..floor.len()).rev() {
+            if !floor[i] {
+                white_count += 1;
+            }
+            dp[i][0] = white_count;
+        }
+
+        for i in (0..floor.len() - 1).rev() {
+            for j in 1..=carpets_num {
+                // 在floor[i]处不放置地毯
+                let a = dp[i + 1][j] + if !floor[i] { 1 } else { 0 };
+                // 在floor[i]处放置地毯
+                // 如果放置的长度超过地板的总长
+                // 则剩余的白色地砖数量必然为0
+                let b = if i + carpet_length >= floor.len() {
+                    0
+                } else {
+                    dp[i + carpet_length][j - 1]
+                };
+                dp[i][j] = a.min(b);
+            }
+        }
+
+        dp[0][carpets_num]
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_2209() {
+        assert_eq!(0, Solution::minimum_white_tiles("11111".to_owned(), 2, 3));
+        assert_eq!(
+            2,
+            Solution::minimum_white_tiles("10110101".to_owned(), 2, 2)
+        );
+    }
+}