Given two strings in lowercase, find the longest string whose permutations are subsequences of given two strings. The output longest string must be sorted.
Input : str1 = "pink", str2 = "kite" Output : "ik" The string "ik" is the longest sorted string whose one permutation "ik" is subsequence of "pink" and another permutation "ki" is subsequence of "kite". Input : str1 = "working", str2 = "women" Output : "now" Input : str1 = "geeks" , str2 = "cake" Output : "ek" Input : str1 = "aaaa" , str2 = "baba" Output : "aa"
The idea is to count characters in both strings.
- calculate frequency of characters for each string and store them in their respective count arrays, say count1 for str1 and count2 for str2.
- Now we have count arrays for 26 characters. So traverse count1 and for any index ‘i’ append character (‘a’+i) in resultant string ‘result’ by min(count1[i], count2[i]) times.
- Since we traverse count array in ascending order, our final string characters will be in sorted order.
- Longest Common Subsequence with at most k changes allowed
- Longest Consecuetive Subsequence when only one insert operation is allowed
- Longest Common Subsequence | DP-4
- LCS (Longest Common Subsequence) of three strings
- Longest Common Anagram Subsequence
- Longest Common Subsequence | DP using Memoization
- Longest Common Increasing Subsequence (LCS + LIS)
- Printing Longest Common Subsequence
- C++ Program for Longest Common Subsequence
- Longest Subsequence with at least one common digit in every element
- Java Program for Longest Common Subsequence
- Python Program for Longest Common Subsequence
- Longest common anagram subsequence from N strings
- Edit distance and LCS (Longest Common Subsequence)
- Length of longest common subsequence containing vowels
Time Complexity: O(m + n) where m and n are lengths of input strings.
Auxiliary Space: O(1)
If you have another approach to solve this problem then please share.
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