{ "data": { "question": { "questionId": "2027", "questionFrontendId": "1898", "boundTopicId": null, "title": "Maximum Number of Removable Characters", "titleSlug": "maximum-number-of-removable-characters", "content": "
You are given two strings s
and p
where p
is a subsequence of s
. You are also given a distinct 0-indexed integer array removable
containing a subset of indices of s
(s
is also 0-indexed).
You want to choose an integer k
(0 <= k <= removable.length
) such that, after removing k
characters from s
using the first k
indices in removable
, p
is still a subsequence of s
. More formally, you will mark the character at s[removable[i]]
for each 0 <= i < k
, then remove all marked characters and check if p
is still a subsequence.
Return the maximum k
you can choose such that p
is still a subsequence of s
after the removals.
A subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.
\n\n\n
Example 1:
\n\n\nInput: s = "abcacb", p = "ab", removable = [3,1,0]\nOutput: 2\nExplanation: After removing the characters at indices 3 and 1, "a\n\nbcacb" becomes "accb".\n"ab" is a subsequence of "accb".\nIf we remove the characters at indices 3, 1, and 0, "abcacb" becomes "ccb", and "ab" is no longer a subsequence.\nHence, the maximum k is 2.\n
Example 2:
\n\n\nInput: s = "abcbddddd", p = "abcd", removable = [3,2,1,4,5,6]\nOutput: 1\nExplanation: After removing the character at index 3, "abc\n\nbddddd" becomes "abcddddd".\n"abcd" is a subsequence of "abcddddd".\n
Example 3:
\n\n\nInput: s = "abcab", p = "abc", removable = [0,1,2,3,4]\nOutput: 0\nExplanation: If you remove the first index in the array removable, "abc" is no longer a subsequence.\n\n\n
\n
Constraints:
\n\n1 <= p.length <= s.length <= 105
0 <= removable.length < s.length
0 <= removable[i] < s.length
p
is a subsequence of s
.s
and p
both consist of lowercase English letters.removable
are distinct.Compiled with clang 11
using the latest C++ 20 standard.
Your code is compiled with level two optimization (-O2
). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
\"], \"java\": [\"Java\", \"OpenJDK 17
. Java 8 features such as lambda expressions and stream API can be used.
Most standard library headers are already included automatically for your convenience.
\\r\\nIncludes Pair
class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.
Python 2.7.12
.
Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
\\r\\n\\r\\nNote that Python 2.7 will not be maintained past 2020. For the latest Python, please choose Python3 instead.
\"], \"c\": [\"C\", \"Compiled with gcc 8.2
using the gnu11 standard.
Your code is compiled with level one optimization (-O1
). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
\\r\\n\\r\\nFor hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:
\\r\\n\\r\\n1. Adding an item to a hash.\\r\\n
\\r\\nstruct hash_entry {\\r\\n int id; /* we'll use this field as the key */\\r\\n char name[10];\\r\\n UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n
2. Looking up an item in a hash:\\r\\n
\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n struct hash_entry *s;\\r\\n HASH_FIND_INT(users, &user_id, s);\\r\\n return s;\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n
3. Deleting an item in a hash:\\r\\n
\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n\\r\\n\"], \"csharp\": [\"C#\", \"\"], \"javascript\": [\"JavaScript\", \"
Node.js 16.13.2
.
Your code is run with --harmony
flag, enabling new ES6 features.
lodash.js library is included by default.
\\r\\n\\r\\nFor Priority Queue / Queue data structures, you may use 5.3.0 version of datastructures-js/priority-queue and 4.2.1 version of datastructures-js/queue.
\"], \"ruby\": [\"Ruby\", \"Ruby 3.1
Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms
\"], \"swift\": [\"Swift\", \"Swift 5.5.2
.
Go 1.21
Support https://godoc.org/github.com/emirpasic/gods@v1.18.1 library.
\"], \"python3\": [\"Python3\", \"Python 3.10
.
Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
\"], \"scala\": [\"Scala\", \"Scala 2.13.7
.
Kotlin 1.9.0
.
Rust 1.58.1
Supports rand v0.6\\u00a0from crates.io
\"], \"php\": [\"PHP\", \"PHP 8.1
.
With bcmath module
\"], \"typescript\": [\"Typescript\", \"TypeScript 5.1.6, Node.js 16.13.2
.
Your code is run with --harmony
flag, enabling new ES2022 features.
lodash.js library is included by default.
\"], \"racket\": [\"Racket\", \"Run with Racket 8.3
.
Dart 2.17.3
\\r\\n\\r\\nYour code will be run directly without compiling
\"]}", "libraryUrl": null, "adminUrl": null, "challengeQuestion": null, "__typename": "QuestionNode" } } }