shortest substring containing all the characters in the set-Square

Author: offamitkumar

Solution/Day-103.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+using namespace std;
+class Solution{
+    public:
+        string minWindow(const string &s , const string &pattern){
+            unordered_map<char , int>st,pt;
+            for(auto&itr:pattern){
+                pt[itr]++;
+            }
+            int start = 0 , end_ = s.size(), i=0;
+            int min_window =INT_MAX;
+            string ans; 
+            int win_size=0;
+            list<char>q;
+            while(i<end_){
+                st[s[i]]++;
+                q.push_back(s[i]);
+                if(pt.find(s[i])!=pt.end()){
+                    win_size++;
+                }
+                if(win_size >= (int)pattern.size()){
+                    while(start < i && (pt.find(s[start])==pt.end() || st[s[start]]-1>=pt[s[start]])){
+                        st[s[start]]--;
+                        q.pop_front();
+                        ++start;
+                    }
+                    string temp(q.begin() , q.end());
+                    if(ans.size()==0 || temp < ans){
+                        ans = temp;
+                    }
+                    min_window = min(min_window , i - start +1);
+                }
+                ++i;
+            }
+            return ans;
+        }
+};
+int main(void){
+    Solution s1;
+    cout << s1.minWindow("figehaeci","aei") << '\n'; 
+    return 0;
+}