feat: add rust solution to lc problem: No.0691

No.0691.Stickers to Spell Word

Author: maolonglong

solution/0600-0699/0691.Stickers to Spell Word/README.md

@@ -217,6 +217,51 @@ func minStickers(stickers []string, target string) int {
 }
 ```
 
+### **Rust**
+
+```rust
+use std::collections::{HashSet, VecDeque};
+
+impl Solution {
+    pub fn min_stickers(stickers: Vec<String>, target: String) -> i32 {
+        let mut q = VecDeque::new();
+        q.push_back(0);
+        let mut ans = 0;
+        let n = target.len();
+        let mut vis = HashSet::new();
+        vis.insert(0);
+        while !q.is_empty() {
+            for _ in 0..q.len() {
+                let state = q.pop_front().unwrap();
+                if state == (1 << n) - 1 {
+                    return ans;
+                }
+                for s in &stickers {
+                    let mut nxt = state;
+                    let mut cnt = [0; 26];
+                    for &c in s.as_bytes() {
+                        cnt[(c - b'a') as usize] += 1;
+                    }
+                    for (i, &c) in target.as_bytes().iter().enumerate() {
+                        let idx = (c - b'a') as usize;
+                        if (nxt & (1 << i)) == 0 && cnt[idx] > 0 {
+                            nxt |= 1 << i;
+                            cnt[idx] -= 1;
+                        }
+                    }
+                    if !vis.contains(&nxt) {
+                        q.push_back(nxt);
+                        vis.insert(nxt);
+                    }
+                }
+            }
+            ans += 1;
+        }
+        -1
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0600-0699/0691.Stickers to Spell Word/README_EN.md

@@ -209,6 +209,51 @@ func minStickers(stickers []string, target string) int {
 }
 ```
 
+### **Rust**
+
+```rust
+use std::collections::{HashSet, VecDeque};
+
+impl Solution {
+    pub fn min_stickers(stickers: Vec<String>, target: String) -> i32 {
+        let mut q = VecDeque::new();
+        q.push_back(0);
+        let mut ans = 0;
+        let n = target.len();
+        let mut vis = HashSet::new();
+        vis.insert(0);
+        while !q.is_empty() {
+            for _ in 0..q.len() {
+                let state = q.pop_front().unwrap();
+                if state == (1 << n) - 1 {
+                    return ans;
+                }
+                for s in &stickers {
+                    let mut nxt = state;
+                    let mut cnt = [0; 26];
+                    for &c in s.as_bytes() {
+                        cnt[(c - b'a') as usize] += 1;
+                    }
+                    for (i, &c) in target.as_bytes().iter().enumerate() {
+                        let idx = (c - b'a') as usize;
+                        if (nxt & (1 << i)) == 0 && cnt[idx] > 0 {
+                            nxt |= 1 << i;
+                            cnt[idx] -= 1;
+                        }
+                    }
+                    if !vis.contains(&nxt) {
+                        q.push_back(nxt);
+                        vis.insert(nxt);
+                    }
+                }
+            }
+            ans += 1;
+        }
+        -1
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0600-0699/0691.Stickers to Spell Word/Solution.rs

@@ -0,0 +1,40 @@
+use std::collections::{HashSet, VecDeque};
+
+impl Solution {
+    pub fn min_stickers(stickers: Vec<String>, target: String) -> i32 {
+        let mut q = VecDeque::new();
+        q.push_back(0);
+        let mut ans = 0;
+        let n = target.len();
+        let mut vis = HashSet::new();
+        vis.insert(0);
+        while !q.is_empty() {
+            for _ in 0..q.len() {
+                let state = q.pop_front().unwrap();
+                if state == (1 << n) - 1 {
+                    return ans;
+                }
+                for s in &stickers {
+                    let mut nxt = state;
+                    let mut cnt = [0; 26];
+                    for &c in s.as_bytes() {
+                        cnt[(c - b'a') as usize] += 1;
+                    }
+                    for (i, &c) in target.as_bytes().iter().enumerate() {
+                        let idx = (c - b'a') as usize;
+                        if (nxt & (1 << i)) == 0 && cnt[idx] > 0 {
+                            nxt |= 1 << i;
+                            cnt[idx] -= 1;
+                        }
+                    }
+                    if !vis.contains(&nxt) {
+                        q.push_back(nxt);
+                        vis.insert(nxt);
+                    }
+                }
+            }
+            ans += 1;
+        }
+        -1
+    }
+}