Maximum Number of Occurrences of a Substring
给一个字符串s, 返回满足条件的substring的最高频率. 这个题问频率, 所以就是counting. 这里不用关心maxsize这个argument.
class Solution {
public int maxFreq(String s, int maxLetters, int minSize, int maxSize) {
Map<String, Integer> map = new HashMap<>();
int max = 0;
for(int i = 0; i + minSize <= s.length(); i++) {
String str = s.substring(i, i + minSize);
Set<Character> set = new HashSet<>();
for(char c : str.toCharArray()) {
set.add(c);
}
if(set.size() <= maxLetters) {
int n = map.getOrDefault(str, 0) + 1;
max = Math.max(max, n);
map.put(str, n);
}
}
return max;
}
}