Merge pull request #1523 from cezarbbb/Backtracking

添加 0039.组合总和 0040.组合总和II Rust版本

problems/0039.组合总和.md

@@ -417,6 +417,35 @@ function combinationSum(candidates: number[], target: number): number[][] {
 };
 ```
 
+## Rust
+
+```Rust
+impl Solution {
+    pub fn backtracking(result: &mut Vec<Vec<i32>>, path: &mut Vec<i32>, candidates: &Vec<i32>, target: i32, mut sum: i32, start_index: usize) {
+        if sum == target { 
+            result.push(path.to_vec());
+            return;
+        }
+        for i in start_index..candidates.len() {
+            if sum + candidates[i] <= target {
+                sum += candidates[i];
+                path.push(candidates[i]);
+                Self::backtracking(result, path, candidates, target, sum, i);
+                sum -= candidates[i];
+                path.pop();
+            }
+        }
+    }
+
+    pub fn combination_sum(candidates: Vec<i32>, target: i32) -> Vec<Vec<i32>> {
+        let mut result: Vec<Vec<i32>> = Vec::new();
+        let mut path: Vec<i32> = Vec::new();
+        Self::backtracking(&mut result, &mut path, &candidates, target, 0, 0);
+        result
+    }
+}
+```
+
 ## C 
 
 ```c

problems/0040.组合总和II.md

@@ -599,6 +599,41 @@ function combinationSum2(candidates: number[], target: number): number[][] {
 };
 ```
 
+## Rust
+
+```Rust
+impl Solution {
+    pub fn backtracking(result: &mut Vec<Vec<i32>>, path: &mut Vec<i32>, candidates: &Vec<i32>, target: i32, mut sum: i32, start_index: usize, used: &mut Vec<bool>) {
+        if sum == target {
+            result.push(path.to_vec());
+            return;
+        }
+        for i in start_index..candidates.len() {
+            if sum + candidates[i] <= target {
+                if i > 0 && candidates[i] == candidates[i - 1] && used[i - 1] == false { continue; }
+                sum += candidates[i];
+                path.push(candidates[i]);
+                used[i] = true;
+                Self::backtracking(result, path, candidates, target, sum, i + 1, used);
+                used[i] = false;
+                sum -= candidates[i];
+                path.pop();
+            }
+        }
+    }
+
+    pub fn combination_sum2(candidates: Vec<i32>, target: i32) -> Vec<Vec<i32>> {
+        let mut result: Vec<Vec<i32>> = Vec::new();
+        let mut path: Vec<i32> = Vec::new();
+        let mut used: Vec<bool> = vec![false; candidates.len()];
+        let mut candidates = candidates;
+        candidates.sort();
+        Self::backtracking(&mut result, &mut path, &candidates, target, 0, 0, &mut used);
+        result
+    }
+}
+```
+
 ## C 
 
 ```c