LeetCode problems solution with cpp.

problem 907

test

ab m xy

m mx my

bm bmx bmy

abm abmx abmy

left

3	1	2	4	1	stack
-1					0
-1	-1				0, 1
-1	-1	1			0, 1, 2
-1	-1	1	2		1, 2, 3
-1	-1	1	2	1	1, 5

right

3	1	2	4	1	stack
				5	4
			4	5	4, 3
		4	4	5	4, 2
	4	4	4	5	4, 1
1	5	4	4	5	4, 1, 0

problem 1670

head stack

problem 828

ABA A 1 AB 2 ABA 2 B 1 BA 2 A 1