leetcode/src/problem/p76_minimum_window_substring.rs
2024-04-29 11:42:45 +08:00

83 lines
1.9 KiB
Rust

/**
* [76] Minimum Window Substring
*/
pub struct Solution {}
// submission codes start here
use std::collections::HashMap;
impl Solution {
pub fn min_window(s: String, t: String) -> String {
let mut t_map = HashMap::new();
for c in t.chars() {
let entry = t_map.entry(c).or_insert(0);
*entry += 1;
}
let s : Vec<char> = s.chars().collect();
let mut s_map = HashMap::new();
let (mut i , mut j) = (0, 0);
let mut result_left = 0;
let mut result_length = usize::MAX;
while j < s.len() {
if t_map.contains_key(&s[j]) {
let entry = s_map.entry(s[j]).or_insert(0);
*entry += 1;
}
while Solution::check_map(&s_map, &t_map) && i <= j {
if j - i + 1 < result_length {
result_length = j - i + 1;
result_left = i;
}
if let Some(entry) = s_map.get_mut(&s[i]) {
*entry -= 1;
}
i += 1;
}
j += 1;
}
if result_length == usize::MAX {
String::new()
} else {
s[result_left..result_left + result_length].iter().collect()
}
}
fn check_map(s : &HashMap<char, i32>, t : &HashMap<char, i32>) -> bool {
for (key, value) in t {
match s.get(key) {
Some(real_value) => {
if *value > *real_value {
return false;
}
}
None => {
return false;
}
}
}
true
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_76() {
assert_eq!("BANC".to_owned(), Solution::min_window("ADOBECODEBANC".to_owned(), "ABC".to_owned()));
}
}