add rust-leetcode #1443

rust-leetcode/README.md

@@ -19,6 +19,7 @@ Leetcode Rust 实现
 * [112 路径总和](src/leetcode_112.rs)
 * [687 最长同值路径](src/leetcode_687.rs)
 * [257 二叉树的所有路径](src/leetcode_257.rs)
+* [1443 收集树上所有苹果的最少时间](src/leetcode_1443.rs)
 
 ### unsafe写法
 

rust-leetcode/src/leetcode_1443.rs

+use std::process::id;
+
+use crate::pre_structs::Solution;
+
+///1443. 收集树上所有苹果的最少时间
+impl Solution {
+    //最少时间能获取全部苹果，也就是说， ret >= 2*苹果的个数
+    //存储子到父的所有路径，求从苹果开始到根节点的节点数量，节点*2就是路径长
+    //用例更新后无法通过，路径存在一对多
+    pub fn min_time_(n: i32, edges: Vec<Vec<i32>>, has_apple: Vec<bool>) -> i32 {
+        let mut visited = vec![false; n as usize];
+        visited[0] = true;
+        let mut ret = 0;
+        let mut reverse_edges = vec![0 as usize; n as usize];
+
+        fn dfs(to: usize, visited: &mut Vec<bool>, reverse_edges: &mut Vec<usize>, ret: &mut i32) {
+            if !visited[to] {
+                visited[to] = true;
+                *ret += 1;
+                dfs(reverse_edges[to], visited, reverse_edges, ret);
+            }
+        }
+
+        for edge in edges.iter() {
+            //记录子 父 路径
+            reverse_edges[edge[1] as usize] = edge[0 as usize] as usize;
+        }
+
+        //遍历所有元素，从苹果开始到根节点
+        for i in 0usize..n as usize {
+            if i < has_apple.len() && has_apple[i] {
+                dfs(i, &mut visited, &mut reverse_edges, &mut ret);
+            }
+        }
+        ret * 2
+    }
+
+    //28~36 ms,63.64%
+    //11 MB,100.00%
+    pub fn min_time(n: i32, edges: Vec<Vec<i32>>, has_apple: Vec<bool>) -> i32 {
+        let mut node_mappings: Vec<Vec<i32>> = vec![Vec::new(); n as usize];
+        let mut reverse_edges = vec![-1i32; n as usize];
+        let mut visited = vec![false; n as usize];
+        visited[0] = true;
+        let mut ret = 0;
+
+        for edge in edges {
+            node_mappings[edge[0usize] as usize].push(edge[1usize]);
+            node_mappings[edge[1usize] as usize].push(edge[0usize]);
+        }
+
+        fn build_reverse_edges(
+            node_mappings: &mut Vec<Vec<i32>>,
+            val: usize,
+            reverse_edges: &mut Vec<i32>,
+        ) {
+            let node = node_mappings[val].clone();
+            for &pairVal in node.iter() {
+                if pairVal != 0 && reverse_edges[pairVal as usize] as i32 == -1i32 {
+                    reverse_edges[pairVal as usize] = val as i32;
+                    build_reverse_edges(node_mappings, pairVal as usize, reverse_edges);
+                }
+            }
+        }
+
+        fn dfs(to: usize, visited: &mut Vec<bool>, reverse_edges: &mut Vec<i32>, ret: &mut i32) {
+            if !visited[to] {
+                visited[to] = true;
+                *ret += 1;
+                dfs(reverse_edges[to] as usize, visited, reverse_edges, ret);
+            }
+        }
+
+        //这一步建了一颗以0为根节点的树，确保能通过子结点找到父结点，父结点记录在reverse_edges数组中
+        build_reverse_edges(&mut node_mappings, 0, &mut reverse_edges);
+        //遍历所有元素，从苹果开始到根节点
+        for i in 0usize..n as usize {
+            if i < has_apple.len() && has_apple[i] {
+                dfs(i, &mut visited, &mut reverse_edges, &mut ret);
+            }
+        }
+        ret * 2
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::pre_structs::Solution;
+
+    #[test]
+    fn min_time() {
+        let n = 7;
+        let edges = vec![[0, 2].to_vec(), [0, 3].to_vec(), [1, 2].to_vec()];
+        let has_apple = vec![false, true, false, false].to_vec();
+
+        let edges2 = vec![
+            [0, 1].to_vec(),
+            [0, 2].to_vec(),
+            [1, 4].to_vec(),
+            [1, 5].to_vec(),
+            [2, 3].to_vec(),
+            [2, 6].to_vec(),
+        ];
+        let has_apple2 = vec![false, false, true, false, true, true, false].to_vec();
+
+        let ret = Solution::min_time(n, edges, has_apple);
+        let ret2 = Solution::min_time(n, edges2, has_apple2);
+        println!("{}", ret);
+        println!("{}", ret2);
+    }
+}

rust-leetcode/src/main.rs

@@ -48,6 +48,7 @@ pub mod leetcode_1385;
 pub mod leetcode_14;
 pub mod leetcode_1403;
 pub mod leetcode_1413;
+pub mod leetcode_1443;
 pub mod leetcode_20;
 pub mod leetcode_204;
 pub mod leetcode_257;