Commit c349f96

committed

solved: Longest Valid Parentheses

1 parent c7280ab commit c349f96Copy full SHA for c349f96

File tree

+68

-0

lines changed

+68

-0

lines changed

Lines changed: 28 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -253,4 +253,32 @@ List<int> findSubstring(String s, List<String> words) {`
`253`	`253`
`254`	`254`	`return startIndexs;`
`255`	`255`	`}`
	`256`	+```
	`257`	`+`
	`258`	`+### Longest Valid Parentheses`
	`259`	`+`
	`260`	+```dart
	`261`	`+int longestValidParentheses(String s) {`
	`262`	`+ if (s.isEmpty) return 0;`
	`263`	`+`
	`264`	`+ int longest = 0;`
	`265`	`+ final List<int> stack = [-1];`
	`266`	`+`
	`267`	`+ for (int i = 0; i < s.length; i++) {`
	`268`	`+ // Open`
	`269`	`+ if (s[i] == '(') {`
	`270`	`+ stack.add(i);`
	`271`	`+ } else {`
	`272`	`+ if (stack.isNotEmpty) stack.removeLast();`
	`273`	`+`
	`274`	`+ if (stack.isNotEmpty) {`
	`275`	`+ longest = max(longest, i - stack.last);`
	`276`	`+ } else {`
	`277`	`+ stack.add(i);`
	`278`	`+ }`
	`279`	`+ }`
	`280`	`+ }`
	`281`	`+`
	`282`	`+ return longest;`
	`283`	`+}`
`256`	`284`	```

Lines changed: 40 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,40 @@`
	`1`	`+import 'dart:math';`
	`2`	`+`
	`3`	`+void main(List<String> args) {`
	`4`	`+ List<String> cases = [`
	`5`	`+ "(()",`
	`6`	`+ ")()())",`
	`7`	`+ "",`
	`8`	`+ "(",`
	`9`	`+ "))",`
	`10`	`+ "((()()",`
	`11`	`+ ];`
	`12`	`+`
	`13`	`+ for (final testcase in cases) {`
	`14`	`+ print(longestValidParentheses(testcase));`
	`15`	`+ }`
	`16`	`+}`
	`17`	`+`
	`18`	`+int longestValidParentheses(String s) {`
	`19`	`+ if (s.isEmpty) return 0;`
	`20`	`+`
	`21`	`+ int longest = 0;`
	`22`	`+ final List<int> stack = [-1];`
	`23`	`+`
	`24`	`+ for (int i = 0; i < s.length; i++) {`
	`25`	`+ // Open`
	`26`	`+ if (s[i] == '(') {`
	`27`	`+ stack.add(i);`
	`28`	`+ } else {`
	`29`	`+ if (stack.isNotEmpty) stack.removeLast();`
	`30`	`+`
	`31`	`+ if (stack.isNotEmpty) {`
	`32`	`+ longest = max(longest, i - stack.last);`
	`33`	`+ } else {`
	`34`	`+ stack.add(i);`
	`35`	`+ }`
	`36`	`+ }`
	`37`	`+ }`
	`38`	`+`
	`39`	`+ return longest;`
	`40`	`+}`

Comments

(0)