You are given an array of
strs, all of the same length.
The strings can be arranged such that there is one on each line, making a grid. For example,
strs = ["abc", "bce", "cae"] can be arranged as:
abc bce cae
You want to delete the columns that are not sorted lexicographically. In the above example (0-indexed), columns 0 (
'c') and 2 (
'e') are sorted while column 1 (
'a') is not, so you would delete column 1.
Return the number of columns that you will delete.
Input: strs = ["cba","daf","ghi"] Output: 1 Explanation: The grid looks as follows: cba daf ghi Columns 0 and 2 are sorted, but column 1 is not, so you only need to delete 1 column.
Input: strs = ["a","b"] Output: 0 Explanation: The grid looks as follows: a b Column 0 is the only column and is sorted, so you will not delete any columns.
Input: strs = ["zyx","wvu","tsr"] Output: 3 Explanation: The grid looks as follows: zyx wvu tsr All 3 columns are not sorted, so you will delete all 3.
n == strs.length
1 <= n <= 100
1 <= strs[i].length <= 1000
strs[i]consists of lowercase English letters.
Check column by column if sorted.
class Solution: def minDeletionSize(self, strs: List[str]) -> int: columns = defaultdict(list) for word in strs: for i in range(len(word)): ch = word[i] columns[i].append(ch) count = 0 for key, value in columns.items(): if value != sorted(value): count += 1 return count
- Time Complexity: O(N))
- Space Complexity: O(N)