LeetCode-in-Java
2825. Make String a Subsequence Using Cyclic Increments
Medium
You are given two 0-indexed strings str1 and str2.
In an operation, you select a set of indices in str1, and for each index i in the set, increment str1[i] to the next character cyclically. That is 'a' becomes 'b', 'b' becomes 'c', and so on, and 'z' becomes 'a'.
Return true if it is possible to make str2 a subsequence of str1 by performing the operation at most once, and false otherwise.
Note: A subsequence of a string is a new string that is formed from the original string by deleting some (possibly none) of the characters without disturbing the relative positions of the remaining characters.
Example 1:
Input: str1 = “abc”, str2 = “ad”
Output: true
Explanation: Select index 2 in str1. Increment str1[2] to become ‘d’. Hence, str1 becomes “abd” and str2 is now a subsequence. Therefore, true is returned.
Example 2:
Input: str1 = “zc”, str2 = “ad”
Output: true
Explanation: Select indices 0 and 1 in str1. Increment str1[0] to become ‘a’. Increment str1[1] to become ‘d’. Hence, str1 becomes “ad” and str2 is now a subsequence. Therefore, true is returned.
Example 3:
Input: str1 = “ab”, str2 = “d”
Output: false
Explanation: In this example, it can be shown that it is impossible to make str2 a subsequence of str1 using the operation at most once. Therefore, false is returned.
Constraints:
1 <= str1.length <= 1051 <= str2.length <= 105str1andstr2consist of only lowercase English letters.
Solution
public class Solution {
public boolean canMakeSubsequence(String str1, String str2) {
int str1ptr = 0;
for (int i = 0; i < str2.length(); i++) {
char c2 = str2.charAt(i);
boolean found = false;
while (str1ptr < str1.length()) {
char c1 = str1.charAt(str1ptr++);
if (c1 == c2 || (c1 - 'a' + 1) % 26 == c2 - 'a') {
found = true;
break;
}
}
if (!found) {
return false;
}
}
return true;
}
}