Skip to content

161-Week08 #1444

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
heyucool wants to merge 1 commit into
base: master
Choose a base branch
from
Open

161-Week08 #1444

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions Week 08/id_161/ReverWords
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
class Solution {
public String reverseOnlyLetters(String S) {
Stack<Character> letters = new Stack();
for (char c: S.toCharArray())
if (Character.isLetter(c))
letters.push(c);

StringBuilder ans = new StringBuilder();
for (char c: S.toCharArray()) {
if (Character.isLetter(c))
ans.append(letters.pop());
else
ans.append(c);
}

return ans.toString();
}
}
18 changes: 18 additions & 0 deletions Week 08/id_161/UniqueChars
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
class Solution {
public int firstUniqChar(String s) {
HashMap<Character, Integer> count = new HashMap<Character, Integer>();
int n = s.length();
// build hash map : character and how often it appears
for (int i = 0; i < n; i++) {
char c = s.charAt(i);
count.put(c, count.getOrDefault(c, 0) + 1);
}

// find the index
for (int i = 0; i < n; i++) {
if (count.get(s.charAt(i)) == 1)
return i;
}
return -1;
}
}