Finish An Activity That Is Back In The Stack

Assume I have activities, like ACT1->ACT2>ACT3, if I open ACT4 I am having ACT1->ACT2->ACT3->ACT4. In this case I want to close ACT1, so I will have only 3 activitie

Solution 1:

using an Array of Activities is doing it's job, beside the use of memory it's ok