Commit ff18480

committed

solved: validate stack sequences

1 parent a71cd76 commit ff18480Copy full SHA for ff18480

File tree

+64

-0

lines changed

+64

-0

lines changed

Lines changed: 26 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -134,4 +134,30 @@ String intToRoman(int num) {`
`134`	`134`
`135`	`135`	`return result.join();`
`136`	`136`	`}`
	`137`	+```
	`138`	`+`
	`139`	`+### Validate Stack Sequences`
	`140`	`+`
	`141`	+```dart
	`142`	`+bool validateStackSequences(List<int> pushed, List<int> popped) {`
	`143`	`+ List<int> current = [];`
	`144`	`+ int indexPush = 0;`
	`145`	`+ int indexPop = 0;`
	`146`	`+`
	`147`	`+ while (indexPush < pushed.length - 1 \|\| indexPop < popped.length - 1) {`
	`148`	`+ if (current.contains(popped[indexPop])) {`
	`149`	`+ if (current.last == popped[indexPop]) {`
	`150`	`+ current.removeLast();`
	`151`	`+ indexPop++;`
	`152`	`+ } else {`
	`153`	`+ return false;`
	`154`	`+ }`
	`155`	`+ } else {`
	`156`	`+ current.add(pushed[indexPush]);`
	`157`	`+ indexPush++;`
	`158`	`+ }`
	`159`	`+ }`
	`160`	`+`
	`161`	`+ return true;`
	`162`	`+}`
`137`	`163`	```

Lines changed: 38 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,38 @@`
	`1`	`+void main(List<String> args) {`
	`2`	`+ List<List<List<int>>> cases = [`
	`3`	`+ [`
	`4`	`+ [1, 2, 3, 4, 5],`
	`5`	`+ [4, 5, 3, 2, 1]`
	`6`	`+ ],`
	`7`	`+ [`
	`8`	`+ [1, 2, 3, 4, 5],`
	`9`	`+ [4, 3, 5, 1, 2]`
	`10`	`+ ]`
	`11`	`+ ];`
	`12`	`+`
	`13`	`+ for (final testcase in cases) {`
	`14`	`+ print(validateStackSequences(testcase.first, testcase.last));`
	`15`	`+ }`
	`16`	`+}`
	`17`	`+`
	`18`	`+bool validateStackSequences(List<int> pushed, List<int> popped) {`
	`19`	`+ List<int> current = [];`
	`20`	`+ int indexPush = 0;`
	`21`	`+ int indexPop = 0;`
	`22`	`+`
	`23`	`+ while (indexPush < pushed.length - 1 \|\| indexPop < popped.length - 1) {`
	`24`	`+ if (current.contains(popped[indexPop])) {`
	`25`	`+ if (current.last == popped[indexPop]) {`
	`26`	`+ current.removeLast();`
	`27`	`+ indexPop++;`
	`28`	`+ } else {`
	`29`	`+ return false;`
	`30`	`+ }`
	`31`	`+ } else {`
	`32`	`+ current.add(pushed[indexPush]);`
	`33`	`+ indexPush++;`
	`34`	`+ }`
	`35`	`+ }`
	`36`	`+`
	`37`	`+ return true;`
	`38`	`+}`

Comments

(0)