We are stacking blocks to form a pyramid. Each block has a color which is a one-letter string.
We are allowed to place any color block C on top of two adjacent blocks of colors A and B, if and only if ABC is an allowed triple.
We start with a bottom row of bottom, represented as a single string. We also start with a list of allowed triples allowed. Each allowed triple is represented as a string of length 3.
Return true if we can build the pyramid all the way to the top, otherwise false.
Example 1:
Input: bottom = "BCD", allowed = ["BCG","CDE","GEA","FFF"]
Output: true
Explanation:
We can stack the pyramid like this:
A
/ \
G E
/ \ / \
B C D
We are allowed to place G on top of B and C because BCG is an allowed triple. Similarly, we can place E on top of C and D, then A on top of G and E.
Example 2:
Input: bottom = "AABA", allowed = ["AAA","AAB","ABA","ABB","BAC"] Output: false Explanation: We cannot stack the pyramid to the top. Note that there could be allowed triples (A, B, C) and (A, B, D) with C != D.
Constraints:
2 <= bottom.length <= 80 <= allowed.length <= 200allowed[i].length == 3- The letters in all input strings are from the set
{'A', 'B', 'C', 'D', 'E', 'F', 'G'}.