feat: add rust solution to lc problem: No.2739 (#1210)

No.2739.Total Distance Traveled

Author: yanglbme

solution/0000-0099/0018.4Sum/README.md

@@ -147,7 +147,7 @@ class Solution {
 public:
     vector<vector<int>> fourSum(vector<int>& nums, int target) {
         int n = nums.size();
-        vector<vector<int> > ans;
+        vector<vector<int>> ans;
         if (n < 4) {
             return ans;
         }

solution/0000-0099/0018.4Sum/README_EN.md

@@ -129,7 +129,7 @@ class Solution {
 public:
     vector<vector<int>> fourSum(vector<int>& nums, int target) {
         int n = nums.size();
-        vector<vector<int> > ans;
+        vector<vector<int>> ans;
         if (n < 4) {
             return ans;
         }

solution/2700-2799/2739.Total Distance Traveled/README.md

@@ -134,6 +134,30 @@ func distanceTraveled(mainTank int, additionalTank int) (ans int) {
 }
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn distance_traveled(mut main_tank: i32, mut additional_tank: i32) -> i32 {
+        let mut cur = 0;
+        let mut ans = 0;
+
+        while main_tank > 0 {
+            cur += 1;
+            main_tank -= 1;
+            ans += 10;
+
+            if cur % 5 == 0 && additional_tank > 0 {
+                additional_tank -= 1;
+                main_tank += 1;
+            }
+        }
+
+        ans
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2700-2799/2739.Total Distance Traveled/README_EN.md

@@ -121,6 +121,30 @@ func distanceTraveled(mainTank int, additionalTank int) (ans int) {
 }
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn distance_traveled(mut main_tank: i32, mut additional_tank: i32) -> i32 {
+        let mut cur = 0;
+        let mut ans = 0;
+
+        while main_tank > 0 {
+            cur += 1;
+            main_tank -= 1;
+            ans += 10;
+
+            if cur % 5 == 0 && additional_tank > 0 {
+                additional_tank -= 1;
+                main_tank += 1;
+            }
+        }
+
+        ans
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2700-2799/2739.Total Distance Traveled/Solution.rs

@@ -0,0 +1,19 @@
+impl Solution {
+    pub fn distance_traveled(mut main_tank: i32, mut additional_tank: i32) -> i32 {
+        let mut cur = 0;
+        let mut ans = 0;
+
+        while main_tank > 0 {
+            cur += 1;
+            main_tank -= 1;
+            ans += 10;
+
+            if cur % 5 == 0 && additional_tank > 0 {
+                additional_tank -= 1;
+                main_tank += 1;
+            }
+        }
+
+        ans
+    }
+}

solution/2700-2799/2742.Painting the Walls/README_EN.md

@@ -42,6 +42,20 @@
 
 ## Solutions
 
+**Solution 1: Memorization**
+
+We can consider whether each wall is painted by a paid painter or a free painter. Design a function $dfs(i, j)$, which means that from the $i$th wall, and the current remaining free painter working time is $j$, the minimum cost of painting all the remaining walls. Then the answer is $dfs(0, 0)$.
+
+The calculation process of function $dfs(i, j)$ is as follows:
+
+-   If $n - i \le j$, it means that there are no more walls than the free painter's working time, so the remaining walls are painted by the free painter, and the cost is $0$;
+-   If $i \ge n$, return $+\infty$;
+-   Otherwise, if the $i$th wall is painted by a paid painter, the cost is $cost[i]$, then $dfs(i, j) = dfs(i + 1, j + time[i]) + cost[i]$; if the $i$th wall is painted by a free painter, the cost is $0$, then $dfs(i, j) = dfs(i + 1, j - 1)$.
+
+Note that the parameter $j$ may be less than $0$. Therefore, in the actual coding process, except for the $Python$ language, we add an offset $n$ to $j$ so that the range of $j$ is $[0, 2n]$.
+
+Time complexity $O(n^2)$, space complexity $O(n^2)$. Where $n$ is the length of the array.
+
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 ### **Python3**