50 lines
1.5 KiB
Rust
50 lines
1.5 KiB
Rust
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fn regex_match(text: &str, regex: &str) -> bool {
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let mut matched = false;
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let text_chars = text.chars().collect();
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let regex_chars = regex.chars().collect();
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rematch(&text_chars, ®ex_chars, 0, 0, &mut matched);
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matched
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}
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fn rematch(text_chars: &Vec<char>,
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regex_chars: &Vec<char>,
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t_idx: usize,
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r_idx: usize,
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matched: &mut bool) {
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// 已经匹配好了，直接返回；
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if *matched { return; }
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// 正则串已经全部匹配
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if r_idx >= regex_chars.len() {
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*matched = true;
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return;
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}
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// 主串已经匹配完，但是正则串还没有全部进行匹配
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if t_idx >= text_chars.len() && r_idx < regex_chars.len() {
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*matched = false;
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return;
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}
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// * 匹配1个或多个字符，递归进行匹配
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if regex_chars[r_idx] == '*' {
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for i in t_idx..text_chars.len() {
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rematch(text_chars, regex_chars, i+1, t_idx+1, matched);
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}
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// ? 匹配0个或1个字符，分两种情况进行匹配
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} else if regex_chars[r_idx] == '?' {
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rematch(text_chars, regex_chars, t_idx+1, r_idx+1, matched);
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rematch(text_chars, regex_chars, t_idx, r_idx+1, matched);
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// 非特殊字符，精确匹配
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} else if regex_chars[r_idx] == text_chars[t_idx] {
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rematch(text_chars, regex_chars, t_idx+1, r_idx+1, matched);
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}
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}
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fn main() {
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let text = "abcdsadfkjlekjoiwjiojieeecd";
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let regex = "ab*eee?d";
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let m = regex_match(text, regex);
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println!("{}", m);
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}
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