You are given a string s
and an integer repeatLimit
. Construct a new string repeatLimitedString
using the characters of s
such that no letter appears more than repeatLimit
times in a row. You do not have to use all characters from s
.
Return the lexicographically largest repeatLimitedString
possible.
A string a
is lexicographically larger than a string b
if in the first position where a
and b
differ, string a
has a letter that appears later in the alphabet than the corresponding letter in b
. If the first min(a.length, b.length)
characters do not differ, then the longer string is the lexicographically larger one.
Example 1:
Input: s = "cczazcc", repeatLimit = 3 Output: "zzcccac" Explanation: We use all of the characters from s to construct the repeatLimitedString "zzcccac". The letter 'a' appears at most 1 time in a row. The letter 'c' appears at most 3 times in a row. The letter 'z' appears at most 2 times in a row. Hence, no letter appears more than repeatLimit times in a row and the string is a valid repeatLimitedString. The string is the lexicographically largest repeatLimitedString possible so we return "zzcccac". Note that the string "zzcccca" is lexicographically larger but the letter 'c' appears more than 3 times in a row, so it is not a valid repeatLimitedString.
Example 2:
Input: s = "aababab", repeatLimit = 2 Output: "bbabaa" Explanation: We use only some of the characters from s to construct the repeatLimitedString "bbabaa". The letter 'a' appears at most 2 times in a row. The letter 'b' appears at most 2 times in a row. Hence, no letter appears more than repeatLimit times in a row and the string is a valid repeatLimitedString. The string is the lexicographically largest repeatLimitedString possible so we return "bbabaa". Note that the string "bbabaaa" is lexicographically larger but the letter 'a' appears more than 2 times in a row, so it is not a valid repeatLimitedString.
Constraints:
1 <= repeatLimit <= s.length <= 105
s
consists of lowercase English letters.
class Solution:
def repeatLimitedString(self, s: str, repeatLimit: int) -> str:
cnt = [0] * 26
for c in s:
cnt[ord(c) - ord('a')] += 1
ans = []
for i in range(25, -1, -1):
j = i - 1
while 1:
for _ in range(min(repeatLimit, cnt[i])):
cnt[i] -= 1
ans.append(chr(ord('a') + i))
if cnt[i] == 0:
break
while j >= 0 and cnt[j] == 0:
j -= 1
if j < 0:
break
cnt[j] -= 1
ans.append(chr(ord('a') + j))
return ''.join(ans)
class Solution {
public String repeatLimitedString(String s, int repeatLimit) {
int[] cnt = new int[26];
for (char c : s.toCharArray()) {
cnt[c - 'a']++;
}
StringBuilder ans = new StringBuilder();
for (int i = 25; i >= 0; --i) {
int j = i - 1;
while (true) {
for (int k = Math.min(repeatLimit, cnt[i]); k > 0; --k) {
cnt[i]--;
ans.append((char) ('a' + i));
}
if (cnt[i] == 0) {
break;
}
while (j >= 0 && cnt[j] == 0) {
--j;
}
if (j < 0) {
break;
}
cnt[j]--;
ans.append((char) ('a' + j));
}
}
return ans.toString();
}
}
class Solution {
public:
string repeatLimitedString(string s, int repeatLimit) {
vector<int> cnt(26);
for (char& c : s) cnt[c - 'a']++;
string ans;
for (int i = 25; ~i; --i) {
int j = i - 1;
while (true) {
for (int k = min(cnt[i], repeatLimit); k; --k) {
cnt[i]--;
ans.push_back('a' + i);
}
if (cnt[i] == 0) break;
while (~j && cnt[j] == 0) --j;
if (j < 0) break;
cnt[j]--;
ans.push_back('a' + j);
}
}
return ans;
}
};