20240806 Finished

This commit is contained in:
jackfiled 2024-08-06 11:45:24 +08:00
parent 552f842be2
commit c7159161af
2 changed files with 90 additions and 1 deletions

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@ -195,4 +195,5 @@ mod p69_sqrtx;
mod p50_powx_n;
mod p149_max_points_on_a_line;
mod p70_climbing_stairs;
mod p198_house_robber;
mod p198_house_robber;
mod p139_word_break;

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@ -0,0 +1,88 @@
/**
* [139] Word Break
*/
pub struct Solution {}
// submission codes start here
use std::{rc::Rc, cell::RefCell, collections::HashMap};
struct Trie {
is_word: bool,
next: HashMap<char, Rc<RefCell<Trie>>>,
}
impl Trie {
fn new(is_word: bool) -> Rc<RefCell<Self>> {
Rc::new(RefCell::new(Trie {
is_word,
next: HashMap::new(),
}))
}
}
impl Solution {
pub fn word_break(s: String, word_dict: Vec<String>) -> bool {
let mut root = Trie::new(false);
// 建立字典树
for word in &word_dict {
let mut node = Rc::clone(&root);
for (i, c) in word.chars().enumerate() {
if node.borrow().next.contains_key(&c) {
if i == word.len() - 1 {
node.borrow().next.get(&c).unwrap().borrow_mut().is_word = true;
}
} else {
if i == word.len() - 1 {
node.borrow_mut().next.insert(c, Trie::new(true));
} else {
node.borrow_mut().next.insert(c, Trie::new(false));
}
}
let tmp_node = Rc::clone(node.borrow().next.get(&c).unwrap());
node = tmp_node;
}
}
let word: Vec<char> = s.chars().collect();
let n = s.len();
let mut dp = vec![false; n];
for i in 0..n {
if i > 0 && !dp[i - 1] {
continue;
}
let mut node = Rc::clone(&root);
let mut pos = i;
while pos < n && node.borrow().next.contains_key(&word[pos]) {
let next_node = Rc::clone(node.borrow().next.get(&word[pos]).unwrap());
dp[pos] = next_node.borrow().is_word || dp[pos];
pos += 1;
node = next_node;
}
}
dp[n - 1]
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_139() {
assert!(Solution::word_break("leetcode".to_owned(), vec_string!("leet", "code")));
assert!(Solution::word_break("applepenapple".to_owned(), vec_string!("apple", "pen")));
assert!(!Solution::word_break("catsandog".to_owned(), vec_string!("cats", "cat", "sand", "and", "cat")));
assert!(Solution::word_break("aaaaaaa".to_owned(), vec_string!("aaa", "aaaa")));
}
}