Minimum Window Substring

Find the shortest contiguous substring of text that contains every character of pattern, including repeats. If several are equally short, return the leftmost.

Implement min_window(text, pattern).

Input

text: The text to search. pattern: The characters that must appear.

Output

Return the shortest window, or an empty string if none exists.

制約

1 ≤ length of text, pattern ≤ 100,000 (ASCII)

例

入力：
text = "ADOBECODEBANC"
pattern = "ABC"

期待される出力：
expected = "BANC"

入力：
std::string text = "ADOBECODEBANC";
std::string pattern = "ABC";

期待される出力：
std::string expected = "BANC";

入力：
string text = "ADOBECODEBANC";
string pattern = "ABC";

期待される出力：
string expected = "BANC";

入力：
text = "a"
pattern = "aa"

期待される出力：
expected = ""

入力：
std::string text = "a";
std::string pattern = "aa";

期待される出力：
std::string expected = "";

入力：
string text = "a";
string pattern = "aa";

期待される出力：
string expected = "";

参考資料

この課題はCodeUtility用に調整されています。上記の説明と制約に従ってください。

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