Given two strings s
and t
of lengths m
and
n respectively, return the minimum window substring ofs
such that every character int
(including duplicates) is included in the window. If there is no such substring, return the empty string""
.
The testcases will be generated such that the answer is unique.
Input: s = "ADOBECODEBANC", t = "ABC" Output: "BANC" Explanation: The minimum window substring "BANC" includes 'A', 'B', and 'C' from string t.
Input: s = "a", t = "a" Output: "a" Explanation: The entire string s is the minimum window.
Input: s = "a", t = "aa" Output: "" Explanation: Both 'a's from t must be included in the window. Since the largest window of s only has one 'a', return empty string.
m == s.length
n == t.length
1 <= m, n <= 105
s
andt
consist of uppercase and lowercase English letters.
Follow up: Could you find an algorithm that runs in O(m + n)
time?
implSolution{pubfnmin_window(s:String,t:String) -> String{if s.len() < t.len(){returnString::new();}let s = s.as_bytes();let t = t.as_bytes();letmut count_s = [0;52];letmut count_t = [0;52];letmut sub_indices = (0, s.len() + 1);letmut i = 0;letmut j = 0;while j < t.len(){match s[j]{b'A'..=b'Z' => count_s[(s[j] - b'A')asusize] += 1, _ => count_s[(s[j] - b'a')asusize + 26] += 1,}match t[j]{b'A'..=b'Z' => count_t[(t[j] - b'A')asusize] += 1, _ => count_t[(t[j] - b'a')asusize + 26] += 1,} j += 1;}if(0..52).all(|k| count_s[k] >= count_t[k]){ sub_indices = (i, j);}while j < s.len(){while j < s.len() && (0..52).any(|k| count_s[k] < count_t[k]){match s[j]{b'A'..=b'Z' => count_s[(s[j] - b'A')asusize] += 1, _ => count_s[(s[j] - b'a')asusize + 26] += 1,} j += 1;}while(0..52).all(|k| count_s[k] >= count_t[k]){if j - i < sub_indices.1 - sub_indices.0{ sub_indices = (i, j);}match s[i]{b'A'..=b'Z' => count_s[(s[i] - b'A')asusize] -= 1, _ => count_s[(s[i] - b'a')asusize + 26] -= 1,} i += 1;}}if sub_indices.1 - sub_indices.0 > s.len(){returnString::new();}String::from_utf8(s[sub_indices.0..sub_indices.1].to_vec()).unwrap()}}