LeetCode-in-Java
467. Unique Substrings in Wraparound String
Medium
We define the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", so s will look like this:
"...zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd....".
Given a string p, return the number of unique non-empty substrings of p are present in s.
Example 1:
Input: p = “a”
Output: 1 Explanation: Only the substring “a” of p is in s.
Example 2:
Input: p = “cac”
Output: 2
Explanation: There are two substrings (“a”, “c”) of p in s.
Example 3:
Input: p = “zab”
Output: 6
Explanation: There are six substrings (“z”, “a”, “b”, “za”, “ab”, and “zab”) of p in s.
Constraints:
1 <= p.length <= 105pconsists of lowercase English letters.
Solution
public class Solution {
public int findSubstringInWraproundString(String p) {
char[] str = p.toCharArray();
int n = str.length;
int[] map = new int[26];
int len = 0;
for (int i = 0; i < n; i++) {
if (i > 0 && ((str[i - 1] + 1 == str[i]) || (str[i - 1] == 'z' && str[i] == 'a'))) {
len += 1;
} else {
len = 1;
}
// we are storing the max len of string for each letter and then we will count all these
// length.
map[str[i] - 'a'] = Math.max(map[str[i] - 'a'], len);
}
int answer = 0;
for (int num : map) {
answer += num;
}
return answer;
}
}