[leetcode 467]Unique Substrings in Wraparound String

Consider the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", so s will look like this: "...zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd....".

Now we have another string p. Your job is to find out how many unique non-empty substrings of p are present in s. In particular, your input is the string p and you need to output the number of different non-empty substrings of p in the string s.

Note: p consists of only lowercase English letters and the size of p might be over 10000.

Example 1:

Input: "a"Output: 1Explanation: Only the substring "a" of string "a" is in the string s.

Example 2:

Input: "cac"Output: 2Explanation: There are two substrings "a", "c" of string "cac" in the string s.

Example 3:

Input: "zab"Output: 6Explanation: There are six substrings "z", "a", "b", "za", "ab", "zab" of string "zab" in the string s.

AC代码：

public class Solution {    public int findSubstringInWraproundString(String p) {         int len = p.length();        if(len == 0 || len ==1 ){            return len;        }        int[] cnt = new int[26];        int tmp = 1;        int res = 0;        for(int i =0 ; i  < len ; ++i){            if(i > 0 && (p.charAt(i) - p.charAt(i-1) == 1 || (p.charAt(i)== 'a' && p.charAt(i-1) == 'z'))){                ++tmp;            }else{                tmp = 1;            }            if(tmp > cnt[p.charAt(i) - 'a']){                res +=(tmp - cnt[p.charAt(i) - 'a']);                cnt[p.charAt(i) - 'a'] = tmp;            }        }        return res;    }}

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