Formatted question description: https://leetcode.ca/all/1910.html
1910. Remove All Occurrences of a Substring
Level
Medium
Description
Given two strings s
and part
, perform the following operation on s
until all occurrences of the substring part
are removed:
- Find the leftmost occurrence of the substring
part
and remove it froms
.
Return s
after removing all occurrences of part
.
A substring is a contiguous sequence of characters in a string.
Example 1:
Input: s = “daabcbaabcbc”, part = “abc”
Output: “dab”
Explanation: The following operations are done:
- s = “daabcbaabcbc”, remove “abc” starting at index 2, so s = “dabaabcbc”.
- s = “dabaabcbc”, remove “abc” starting at index 4, so s = “dababc”.
- s = “dababc”, remove “abc” starting at index 3, so s = “dab”.
Now s has no occurrences of “abc”.
Example 2:
Input: s = “axxxxyyyyb”, part = “xy”
Output: “ab”
Explanation: The following operations are done:
- s = “axxxxyyyyb”, remove “xy” starting at index 4 so s = “axxxyyyb”.
- s = “axxxyyyb”, remove “xy” starting at index 3 so s = “axxyyb”.
- s = “axxyyb”, remove “xy” starting at index 2 so s = “axyb”.
- s = “axyb”, remove “xy” starting at index 1 so s = “ab”.
Now s has no occurrences of “xy”.
Constraints:
1 <= s.length <= 1000
1 <= part.length <= 1000
s
andpart
consists of lowercase English letters.
Solution
Use indexOf
to find the index of the occurrence of part
in s
, and remove the corresponding substring from s
. Repeat this step until s
does not contain part. Finally, return
s`.
class Solution {
public String removeOccurrences(String s, String part) {
int partLength = part.length();
while (s.indexOf(part) >= 0) {
int index = s.indexOf(part);
s = s.substring(0, index) + s.substring(index + partLength);
}
return s;
}
}