[Leetcode] Min Stack

The idea was to use the stacks.

pushfor, the first stack records the pushed elements and the second stacks records all the minimum (including du Plicates) that has been seen.

popfor, we need-compare with the top elements of the stacks. If They is equal (the top element is also minimum, popping it out would change the minimum), pop both; Otherwise, only pops the first stack.

The remaining and would be trivial:just return the top element of the first and top getMin second stack respectively.

The code is as follows.

1 classMinstack {2  Public:3     voidPushintx) {4         if(Stk1.empty () | | | x <=stk2.top ())5 Stk2.push (x);6 Stk1.push (x);7     }8 9     voidpop () {Ten         if(Stk1.top () = =stk2.top ()) One Stk2.pop (); A Stk1.pop (); -     } -  the     intTop () { -         returnstk1.top (); -     } -  +     intgetmin () { -         returnstk2.top (); +     } A Private: atstack<int>Stk1; -stack<int>stk2; -};

[Leetcode] Min Stack