leetcode@ [30/76] Substring with Concatenation of All Words & Minimum Window Substring (Hashtable, Two Pointers)

class Solution {
public:
    bool func(string s, vector<string>& words, map<string, int>& h) {
        int n = words.size();
        int each = words[0].length();
        
        map<string, int> mh; mh.clear();
        int i = 0;
        for(; i<=s.length()-each; i+=each) {
            string sub = s.substr(i, each);
            
            if(h.find(sub) != h.end()) {
                ++mh[sub];
                if(mh[sub] > h[sub]) return false;
            }
            else return false;
        }
        
        return true;
    }
    
    vector<int> findSubstring(string s, vector<string>& words) {
        vector<int> res;
        int n = words.size();
        if(n == 0)  return res;
        
        map<string, int> h;
        for(int i=0; i<n; ++i) {
            if(h.find(words[i]) == h.end()) {
                h.insert(make_pair(words[i], 1));
            }
            else {
                h[words[i]]++;
            }
        }
        int each = words[0].length();
        int tot = each * n;
        if(s.length() < tot) return res;
        
        for(int i = 0; i <= s.length() - tot; ++i) {
            string sub = s.substr(i, tot);
            //cout << sub << endl;
            if(func(sub, words, h))  res.push_back(i);
        }
        
        return res;
    }
};

class Solution {
public:
    string minWindow(string s, string t) {
        if(s.length() == 0 || s.length() < t.length())  return "";
        if(s.length() == t.length()) {
            if(s == t)  return s;
        }
        
        map<char, int> h; h.clear();
        map<char, bool> mh; mh.clear();
        for(int i=0; i<t.length(); ++i) {
            h[t[i]]++;
            mh[t[i]] = true;
        }
        
        int cnt = t.length(), l = 0, minRange = INT_MAX, mini, minj;
        for(int r=0; r<s.length(); ++r) {
            if(mh[s[r]]) {
                --h[s[r]];
                if(h[s[r]] >= 0)  --cnt;
            }
            
            if(cnt == 0) {
                while(!mh[s[l]] || h[s[l]] < 0) {
                    ++h[s[l]];
                    ++l;
                }
                
                if(minRange > r - l + 1) {
                    minRange = r - l + 1;
                    mini = l;
                }
            }
        }

        if(minRange == INT_MAX)  return "";
        
        return s.substr(mini, minRange);
    }
};