Given a 0-indexed array of strings words where words[i] is either a positive integer represented as a string or the string "prev".
Start iterating from the beginning of the array; for every "prev" string seen in words, find the last visited integer in words which is defined as follows:
k be the number of consecutive "prev" strings seen so far (containing the current string). Let nums be the 0-indexed array of integers seen so far and nums_reverse be the reverse of nums, then the integer at (k - 1)th index of nums_reverse will be the last visited integer for this "prev".k is greater than the total visited integers, then the last visited integer will be -1.Return an integer array containing the last visited integers.
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Example 1:
\n\n\nInput: words = ["1","2","prev","prev","prev"]\nOutput: [2,1,-1]\nExplanation: \nFor "prev" at index = 2, last visited integer will be 2 as here the number of consecutive "prev" strings is 1, and in the array reverse_nums, 2 will be the first element.\nFor "prev" at index = 3, last visited integer will be 1 as there are a total of two consecutive "prev" strings including this "prev" which are visited, and 1 is the second last visited integer.\nFor "prev" at index = 4, last visited integer will be -1 as there are a total of three consecutive "prev" strings including this "prev" which are visited, but the total number of integers visited is two.\n\n\n
Example 2:
\n\n\nInput: words = ["1","prev","2","prev","prev"]\nOutput: [1,2,1]\nExplanation:\nFor "prev" at index = 1, last visited integer will be 1.\nFor "prev" at index = 3, last visited integer will be 2.\nFor "prev" at index = 4, last visited integer will be 1 as there are a total of two consecutive "prev" strings including this "prev" which are visited, and 1 is the second last visited integer.\n\n\n
\n
Constraints:
\n\n1 <= words.length <= 100words[i] == "prev" or 1 <= int(words[i]) <= 100Compiled with clang 11 using the latest C++ 20 standard.
Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
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