weekly-83 (#4)

some weekly

Author: hxzhao527

Makefile

@@ -1,10 +1,11 @@
 .PHONY: clean coverage
 
 clean:
-	cargo clean
+	@cargo clean; \
+	rm *.profraw
 test:
-	cargo test
+	@cargo test
 coverage: test
-	grcov target/coverage/grcov.profraw --branch --ignore-not-existing --binary-path ./target/debug/ -s . -t lcov --ignore \"/*\" -o target/coverage/lcov.info
+	@grcov target/coverage/grcov.profraw --branch --ignore-not-existing --binary-path ./target/debug/ -s . -t lcov --ignore \"/*\" -o target/coverage/lcov.info
 lint:
-	cargo fix --allow-dirty --allow-staged
+	@cargo fix --allow-dirty --allow-staged

ReadMe.md

@@ -17,6 +17,8 @@
   - [LeetCode][leetcode]
 - 语言: [Rust][rust]
 - IDE: [我的 IDE 配置][我的ide 配置]
+- 一些辅助工具
+  - [LaTeX公式编辑器](https://www.latexlive.com/##)
 
 ### 内容
 

src/array/ext/disjoint.rs

@@ -40,6 +40,7 @@ impl UnionFind {
         }
         root
     }
+
     pub fn is_connected(&self, p: usize, q: usize) -> bool {
         self.find(p) == self.find(q)
     }
@@ -74,7 +75,7 @@ pub fn find_circle_num(is_connected: Vec<Vec<i32>>) -> i32 {
 
 /// [684. 冗余连接](https://leetcode.cn/problems/redundant-connection/)
 pub fn find_redundant_connection(edges: Vec<Vec<i32>>) -> Vec<i32> {
-    let mut uf = UnionFind::new(edges.len()+1);
+    let mut uf = UnionFind::new(edges.len() + 1);
     let mut curr_count = uf.count();
     let mut last_edge = vec![];
 
@@ -90,11 +91,206 @@ pub fn find_redundant_connection(edges: Vec<Vec<i32>>) -> Vec<i32> {
     last_edge
 }
 
+/// [990. 等式方程的可满足性](https://leetcode.cn/problems/satisfiability-of-equality-equations/)
+pub fn equations_possible(equations: Vec<String>) -> bool {
+    let mut uf = UnionFind::new(26);
+
+    let mut not_equal = vec![]; // 暂存
+
+    for e in equations {
+        let s = e.as_bytes();
+        let (a, b, eq) = (s[0] - b'a', s[3] - b'a', s[1] == b'=');
+        if eq {
+            uf.connect(a as usize, b as usize);
+        } else {
+            not_equal.push((a as usize, b as usize));
+        }
+    }
+
+    for (a, b) in not_equal {
+        if uf.is_connected(a, b) {
+            return false;
+        }
+    }
+    true
+}
+
+/// [839. 相似字符串组](https://leetcode.cn/problems/similar-string-groups/)
+pub fn num_similar_groups(strs: Vec<String>) -> i32 {
+    fn is_similar(s1: &str, s2: &str) -> bool {
+        s1.chars().zip(s2.chars()).filter(|(a, b)| !a.eq(b)).count() <= 2
+    }
+    let mut uf = UnionFind::new(strs.len());
+
+    for i in 0..strs.len() {
+        let s1 = strs.get(i).unwrap();
+        for j in i + 1..strs.len() {
+            if uf.is_connected(i, j) {
+                continue;
+            }
+
+            let s2 = strs.get(j).unwrap();
+            if is_similar(s1, s2) {
+                uf.connect(i, j);
+            }
+        }
+    }
+    uf.count() as i32
+}
+
+/// [841. 钥匙和房间](https://leetcode.cn/problems/keys-and-rooms/)
+///
+/// 关键信息: 除 `0` 号房间外的其余所有房间都被锁住
+///
+/// 解法1: bfs
+/// ```
+/// pub fn can_visit_all_rooms(rooms: Vec<Vec<i32>>) -> bool {
+///     use std::collections::HashSet;
+///     use std::collections::VecDeque;
+///
+///     let mut queue = VecDeque::new();
+///     let mut visited = HashSet::new();
+///
+///     queue.push_back(0);
+///     visited.insert(0);
+///     while let Some(n) = queue.pop_front() {
+///         let room = rooms.get(n).unwrap();
+///         for &r in room.iter(){
+///             if !visited.insert(r) {
+///                 continue;
+///             }
+///             queue.push_back(r as usize)
+///         }
+///     }
+///     visited.len() == rooms.len()
+/// }
+/// ```
+///
+/// 解法二: 并查集
+///
+/// 由于 `HashSet` 这里也只是用了 `insert` 和 `contain` 两个方法, 因此换成 并查集判定也是OK的.
+/// 甚至内存表现上, 并查集更优.
+pub fn can_visit_all_rooms(rooms: Vec<Vec<i32>>) -> bool {
+    use std::collections::VecDeque;
+    let mut uf = UnionFind::new(rooms.len());
+
+    let mut queue = VecDeque::new();
+
+    queue.push_back(0);
+    while let Some(curr) = queue.pop_front() {
+        let room = rooms.get(curr).unwrap();
+        for &r in room.iter() {
+            if uf.is_connected(curr, r as usize) {
+                continue;
+            }
+            uf.connect(curr, r as usize);
+            queue.push_back(r as usize);
+        }
+    }
+    uf.count() == 1
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
     use crate::vec2;
 
+    #[test]
+    fn test_can_visit_all_rooms() {
+        struct Testcase {
+            rooms: Vec<Vec<i32>>,
+            expect: bool,
+        }
+
+        vec![
+            Testcase {
+                rooms: vec2![[1], [2], [3], []],
+                expect: true,
+            },
+            Testcase {
+                rooms: vec2![[1, 3], [3, 0, 1], [2], [0]],
+                expect: false,
+            },
+            Testcase {
+                rooms: vec2![[1], [], [0, 3], [1]],
+                expect: false,
+            },
+        ]
+        .into_iter()
+        .enumerate()
+        .for_each(|(idx, testcase)| {
+            let Testcase { rooms, expect } = testcase;
+            let actual = can_visit_all_rooms(rooms);
+            assert_eq!(expect, actual, "case {} failed", idx);
+        });
+    }
+
+    #[test]
+    fn test_num_similar_groups() {
+        struct TestCase {
+            strs: Vec<&'static str>,
+            expect: i32,
+        }
+
+        vec![
+            TestCase {
+                strs: vec!["tars", "rats", "arts", "star"],
+                expect: 2,
+            },
+            TestCase {
+                strs: vec!["omv", "ovm"],
+                expect: 1,
+            },
+        ]
+        .into_iter()
+        .enumerate()
+        .for_each(|(idx, testcase)| {
+            let TestCase { strs, expect } = testcase;
+            let strs = strs.into_iter().map(str::to_string).collect();
+            let actual = num_similar_groups(strs);
+            assert_eq!(expect, actual, "case {} failed", idx);
+        });
+    }
+
+    #[test]
+    fn test_equations_possible() {
+        struct TestCase {
+            equations: Vec<&'static str>,
+            expect: bool,
+        }
+
+        vec![
+            TestCase {
+                equations: vec!["a==b", "b!=a"],
+                expect: false,
+            },
+            TestCase {
+                equations: vec!["b==a", "a==b"],
+                expect: true,
+            },
+            TestCase {
+                equations: vec!["a==b", "b==c", "a==c"],
+                expect: true,
+            },
+            TestCase {
+                equations: vec!["a==b", "b!=c", "c==a"],
+                expect: false,
+            },
+            TestCase {
+                equations: vec!["c==c", "b==d", "x!=z"],
+                expect: true,
+            },
+        ]
+        .into_iter()
+        .enumerate()
+        .for_each(|(idx, testcase)| {
+            let TestCase { equations, expect } = testcase;
+            let equations = equations.into_iter().map(str::to_string).collect();
+            let actual = equations_possible(equations);
+            assert_eq!(expect, actual, "case {} failed", idx);
+        });
+    }
+
     #[test]
     fn test_find_redundant_connection() {
         struct Testcase {