Package g0101_0200.s0115_distinct_subsequences

Class Solution

java.lang.Object
g0101_0200.s0115_distinct_subsequences.Solution
public class Solution extends java.lang.Object
115 - Distinct Subsequences.

Hard

Given two strings s and t, return the number of distinct subsequences of s which equals t.

A string’s subsequence is a new string formed from the original string by deleting some (can be none) of the characters without disturbing the remaining characters’ relative positions. (i.e., "ACE" is a subsequence of "ABCDE" while "AEC" is not).

It is guaranteed the answer fits on a 32-bit signed integer.

Example 1:

Input: s = “rabbbit”, t = “rabbit”

Output: 3

Explanation: As shown below, there are 3 ways you can generate “rabbit” from S. **rabb**b**it** **ra**b**bbit** **rab**b**bit**

Example 2:

Input: s = “babgbag”, t = “bag”

Output: 5

Explanation: As shown below, there are 5 ways you can generate “bag” from S. **ba**b**g**bag **ba**bgba**g** **b**abgb**ag** ba**b**gb**ag** babg**bag**

Constraints:

  • 1 <= s.length, t.length <= 1000
  • s and t consist of English letters.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numDistinct(java.lang.String text, java.lang.String text2)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • numDistinct

      public int numDistinct(java.lang.String text, java.lang.String text2)