Merge pull request neetcode-gh#1956 from laitooo/0020-valid-parenthes…

…es.dart Create: 0020-Valid-Parentheses.dart
Gyanachand1 · Jan 9, 2023 · 1609f47 · 1609f47
2 parents 53778be + 7e49102
commit 1609f47
Showing 1 changed file with 36 additions and 0 deletions.
diff --git a/dart/0020-valid-parentheses.dart b/dart/0020-valid-parentheses.dart
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+class Solution {
+ bool isValid(String s) {
+ var res = [];
+ for (int i=0; i<s.length; i++) {
+ if (s[i] != ']' && s[i] != ')' && s[i] != '}') {
+ res.add(s[i]);
+ continue;
+ } else {
+ if (res.isEmpty) {
+ return false;
+ }
+ }
+
+ if (s[i] == ']') {
+ if (res.last == '[') {
+ res.removeLast();
+ } else {
+ return false;
+ }
+ } else if (s[i] == ')') {
+ if (res.last == '(') {
+ res.removeLast();
+ } else {
+ return false;
+ }
+ } else if (s[i] == '}') {
+ if (res.last == '{') {
+ res.removeLast();
+ } else {
+ return false;
+ }
+ }
+ }
+ return res.length == 0;
+ }
+}