int longestSubstring(string s, int k)
{
if (s=="") return 0;
unordered_map<char,int>Map;
for (int i=0; i<s.size(); i++)
Map[s[i]]++;
unordered_set<char>Set;
for (auto a:Map)
{
if (a.second>=k)
Set.insert(a.first);
}
if (Set.size()==Map.size())
return s.size();
int result=0;
for (int i=0; i<s.size(); i++)
{
int i0=i;
while (i<s.size() && Set.find(s[i])!=Set.end())
i++;
result = max(result, longestSubstring(s.substr(i0,i-i0),k));
}
return result;
}
int longestSubstring(string s, int k) {
if (k <= 1) return s.size();
unordered_map<char, int> myMap;
for (char c : s) myMap[c]++;
int n = s.size(), ret = 0, cur = 0, i = 0;
for (i = 0; i < n; i++) {
if (myMap[s[i]] < k) break;
}
if (i == n) return s.size();
ret = max(longestSubstring(s.substr(0, i), k), longestSubstring(s.substr(i + 1), k));
return ret;
}
int longestSubstring(string s, int k) {
if (s.size() < k)
return 0;
int result = s.size();
vector<int> chars(26, 0);
for (int i = 0; i < s.size(); i++) {
chars[s[i] - 'a']++;
}
int i;
for (i = 0; i < s.size(); i++) {
if (chars[s[i] - 'a'] < k) {
break;
}
}
if (i == s.size()) return s.size();
return max(longestSubstring(s.substr(0, i), k), longestSubstring(s.substr(i + 1), k));
}
int longestSubstring(string s, int k)
{
if(s.size() < k) return 0;
int c[200] = {0};
for(char i : s) ++c[i];
int len = s.size();
for(int i = 0; i < len; ++i)
{
if(c[s[i]] && c[s[i]] < k)
{
string l = s.substr(0, i);
string r = s.substr(i+1);
return max(longestSubstring(l,k),longestSubstring(r,k));
}
}
return len;
}
int longestSubstring(string s, int k) {
if (k > (int)s.size()) {
return 0;
}
vector<int> cnt(26, 0);
for (int i = 0; i < (int)s.size(); ++i) ++cnt[s[i] - 'a'];
int mn = INT_MAX;
for (int i = 0; i < 26; ++i) {
if (cnt[i] > 0) mn = min(cnt[i], mn);
}
if (mn >= k) return s.size();
int pv = 0;
int res = 0;
for (int i = 0; i < (int)s.size(); ++i) {
if (cnt[s[i] - 'a'] < k) {
res = max(res, longestSubstring(s.substr(pv, i - pv), k));
pv = i + 1;
}
}
res = max(res, longestSubstring(s.substr(pv, s.size() - pv), k));
return res;
}
int longestSubstring(string s, int k) {
//deal with edge cases
if (s.size() == 0 || s.size() < k) return 0;
if (k==1) return s.size();
//declare a map for every char's counter
int count[NO_OF_CHARS];
memset(count , 0, sizeof(count));
//counting every char
for (char ch : s) {
count[ch]++;
}
int i=0;
for ( i=0; i<NO_OF_CHARS; i++) {
if (count[i] !=0 && count[i] < k) break;
}
//all of the chars meet the requirement
if ( i >= NO_OF_CHARS ) return s.size();
// find the most infrequent char
char least = 0;
for (int c = 0; c < NO_OF_CHARS; c++) {
if (count[c] == 0) continue;
if (least == 0) {
least = c;
} else if ( count[c] < count[least]) {
least = c;
}
}
//split the string and run them recursively
vector<string> subs;
split(s, least, subs);
int res = 0;
for (string str: subs) {
res = max(res, longestSubstring(str, k));
}
return res;
return 0;
}
