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1 | 1 | package com.fishercoder.solutions;
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2 | 2 |
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3 |
| -/**Consider the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", so s will look like this: "...zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd....". |
4 |
| -
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5 |
| - 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. |
6 |
| -
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7 |
| - Note: p consists of only lowercase English letters and the size of p might be over 10000. |
| 3 | +/** |
| 4 | + * 467. Unique Substrings in Wraparound String |
| 5 | + * |
| 6 | + * Consider the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", |
| 7 | + * so s will look like this: "...zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd....". |
| 8 | + * Now we have another string p. |
| 9 | + * Your job is to find out how many unique non-empty substrings of p are present in s. |
| 10 | + * 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. |
| 11 | + * Note: p consists of only lowercase English letters and the size of p might be over 10000. |
8 | 12 |
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9 | 13 | Example 1:
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10 | 14 | Input: "a"
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11 | 15 | Output: 1
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12 |
| -
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13 | 16 | Explanation: Only the substring "a" of string "a" is in the string s.
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| 17 | +
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14 | 18 | Example 2:
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15 | 19 | Input: "cac"
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16 | 20 | Output: 2
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17 | 21 | Explanation: There are two substrings "a", "c" of string "cac" in the string s.
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| 22 | +
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18 | 23 | Example 3:
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19 | 24 | Input: "zab"
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20 | 25 | Output: 6
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21 |
| - Explanation: There are six substrings "z", "a", "b", "za", "ab", "zab" of string "zab" in the string s.*/ |
| 26 | + Explanation: There are six substrings "z", "a", "b", "za", "ab", "zab" of string "zab" in the string s. |
| 27 | + */ |
22 | 28 | public class _467 {
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23 |
| - /**A naive solution would definitely result in TLE. |
24 |
| - * Since the pattern keeps repeating, DP is the way to go. |
25 |
| - * Because the input consists merely of lowercase English letters, we could maintain an array of size 26, |
26 |
| - * keep updating this array, counting the substrings that end with this letter, keep updating it with the largest one possible. |
27 |
| - * |
28 |
| - * Inspired by this: https://discuss.leetcode.com/topic/70658/concise-java-solution-using-dp*/ |
29 |
| - public static int findSubstringInWraproundString(String p) { |
30 |
| - if (p == null || p.isEmpty()) { |
31 |
| - return 0; |
32 |
| - } |
33 |
| - if (p.length() < 2) { |
34 |
| - return p.length(); |
35 |
| - } |
36 |
| - int count = 0; |
37 |
| - int[] dp = new int[26]; |
38 |
| - dp[p.charAt(0) - 'a'] = 1; |
39 |
| - int len = 1; |
40 |
| - for (int i = 1; i < p.length(); i++) { |
41 |
| - if (p.charAt(i) - 1 == p.charAt(i - 1) || (p.charAt(i) == 'a' && p.charAt(i - 1) == 'z')) { |
42 |
| - len++; |
43 |
| - } else { |
44 |
| - len = 1; |
| 29 | + public static class Solution1 { |
| 30 | + /** |
| 31 | + * A naive solution would definitely result in TLE. |
| 32 | + * Since the pattern keeps repeating, DP is the way to go. |
| 33 | + * Because the input consists merely of lowercase English letters, we could maintain an array of size 26, |
| 34 | + * keep updating this array, counting the substrings that end with this letter, keep updating it with the largest one possible. |
| 35 | + * <p> |
| 36 | + * Inspired by this: https://discuss.leetcode.com/topic/70658/concise-java-solution-using-dp |
| 37 | + */ |
| 38 | + public int findSubstringInWraproundString(String p) { |
| 39 | + if (p == null || p.isEmpty()) { |
| 40 | + return 0; |
| 41 | + } |
| 42 | + if (p.length() < 2) { |
| 43 | + return p.length(); |
| 44 | + } |
| 45 | + int count = 0; |
| 46 | + int[] dp = new int[26]; |
| 47 | + dp[p.charAt(0) - 'a'] = 1; |
| 48 | + int len = 1; |
| 49 | + for (int i = 1; i < p.length(); i++) { |
| 50 | + if (p.charAt(i) - 1 == p.charAt(i - 1) || (p.charAt(i) == 'a' && p.charAt(i - 1) == 'z')) { |
| 51 | + len++; |
| 52 | + } else { |
| 53 | + len = 1; |
| 54 | + } |
| 55 | + dp[p.charAt(i) - 'a'] = Math.max(len, dp[p.charAt(i) - 'a']); |
45 | 56 | }
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46 |
| - dp[p.charAt(i) - 'a'] = Math.max(len, dp[p.charAt(i) - 'a']); |
47 |
| - } |
48 | 57 |
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49 |
| - for (int i : dp) { |
50 |
| - count += i; |
| 58 | + for (int i : dp) { |
| 59 | + count += i; |
| 60 | + } |
| 61 | + return count; |
51 | 62 | }
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52 |
| - return count; |
53 | 63 | }
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54 | 64 |
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55 |
| - public static void main(String... args) { |
56 |
| -// String p = "a"; |
57 |
| -// String p = "abcgha"; |
58 |
| - String p = "zab"; |
59 |
| - System.out.println(findSubstringInWraproundString(p)); |
60 |
| - } |
61 | 65 | }
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