add: 到达首都的最少油耗

README.md

@@ -481,6 +481,10 @@ Rust标准库`std::collections`提供了4种通用容器类型，包含一下8
 
 ### 图
 
+- [到达首都的最少油耗](src/graphs/minimum_fuel_cost_to_report_to_the_capital.rs)  [树, 深度优先搜索, 广度优先搜索, 图]
+
+  - LeetCode 2477. 到达首都的最少油耗 <https://leetcode.cn/problems/minimum-fuel-cost-to-report-to-the-capital>
+
 - [T 秒后青蛙的位置](src/graphs/frog_position_after_t_seconds.rs)  [树, 深度优先搜索, 广度优先搜索, 图]
 
   - LeetCode 1377. T 秒后青蛙的位置 <https://leetcode.cn/problems/frog-position-after-t-seconds>

src/graphs/minimum_fuel_cost_to_report_to_the_capital.rs

@@ -0,0 +1,39 @@
+// 到达首都的最少油耗
+// https://leetcode.cn/problems/minimum-fuel-cost-to-report-to-the-capital
+// INLINE  ../../images/graphs/minimum_fuel_cost_to_report_to_the_capital.jpeg
+
+pub struct Solution;
+
+impl Solution {
+    pub fn minimum_fuel_cost(roads: Vec<Vec<i32>>, seats: i32) -> i64 {
+        let n = roads.len() + 1;
+        let mut graph = vec![vec![]; n];
+        for road in &roads {
+            let (src, dest): (usize, usize) = (road[0] as usize, road[1] as usize);
+            graph[src].push(dest);
+            graph[dest].push(src);
+        }
+
+        fn traverse(
+            node: usize,
+            parent: i32,
+            graph: &Vec<Vec<usize>>,
+            cost: &mut i64,
+            seats: i32,
+        ) -> i32 {
+            let mut total = 1;
+            for &neighbor in &graph[node] {
+                if neighbor as i32 != parent {
+                    let sub_total = traverse(neighbor, node as i32, graph, cost, seats);
+                    *cost += ((sub_total + seats - 1) / seats) as i64;
+                    total += sub_total;
+                }
+            }
+            total
+        }
+
+        let mut cost = 0;
+        traverse(0, -1, &graph, &mut cost, seats);
+        cost
+    }
+}

src/graphs/mod.rs

@@ -1,3 +1,4 @@
 pub mod find_the_town_judge;
 pub mod flower_planting_with_no_adjacent;
 pub mod frog_position_after_t_seconds;
+pub mod minimum_fuel_cost_to_report_to_the_capital;

tests/graphs/minimum_fuel_cost_to_report_to_the_capital_test.rs

@@ -0,0 +1,50 @@
+use rust_practice::graphs::minimum_fuel_cost_to_report_to_the_capital::Solution;
+
+#[test]
+fn minimum_fuel_cost() {
+    // 示例 1：
+    // 输入：roads = [[0,1],[0,2],[0,3]], seats = 5
+    // 输出：3
+    // 解释：
+    // - 代表 1 直接到达首都，消耗 1 升汽油。
+    // - 代表 2 直接到达首都，消耗 1 升汽油。
+    // - 代表 3 直接到达首都，消耗 1 升汽油。
+    // 最少消耗 3 升汽油。
+
+    let roads1 = vec![vec![0, 1], vec![0, 2], vec![0, 3]];
+    let seats1 = 5;
+    assert_eq!(Solution::minimum_fuel_cost(roads1, seats1), 3);
+
+    // 示例 2：
+    // 输入：roads = [[3,1],[3,2],[1,0],[0,4],[0,5],[4,6]], seats = 2
+    // 输出：7
+    // 解释：
+    // - 代表 2 到达城市 3 ，消耗 1 升汽油。
+    // - 代表 2 和代表 3 一起到达城市 1 ，消耗 1 升汽油。
+    // - 代表 2 和代表 3 一起到达首都，消耗 1 升汽油。
+    // - 代表 1 直接到达首都，消耗 1 升汽油。
+    // - 代表 5 直接到达首都，消耗 1 升汽油。
+    // - 代表 6 到达城市 4 ，消耗 1 升汽油。
+    // - 代表 4 和代表 6 一起到达首都，消耗 1 升汽油。
+    // 最少消耗 7 升汽油。
+
+    let roads2 = vec![
+        vec![3, 1],
+        vec![3, 2],
+        vec![1, 0],
+        vec![0, 4],
+        vec![0, 5],
+        vec![4, 6],
+    ];
+    let seats2 = 2;
+    assert_eq!(Solution::minimum_fuel_cost(roads2, seats2), 7);
+
+    // 示例 3：
+    // 输入：roads = [], seats = 1
+    // 输出：0
+    // 解释：没有代表需要从别的城市到达首都。
+
+    let roads3 = vec![];
+    let seats3 = 1;
+    assert_eq!(Solution::minimum_fuel_cost(roads3, seats3), 0);
+}

tests/graphs/mod.rs

@@ -1,3 +1,4 @@
 pub mod find_the_town_judge_test;
 pub mod flower_planting_with_no_adjacent_test;
 pub mod frog_position_after_t_seconds_test;
+pub mod minimum_fuel_cost_to_report_to_the_capital_test;