Added file for count occurences of anagrams

Count_Occurences_of_Anagrams.cpp

@@ -0,0 +1,53 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define IO() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
+
+int main(){
+
+	IO();
+
+	string s = "forxxorfxdofr";
+	string anagram = "for";
+	int k = anagram.size();
+
+	unordered_map<char,int> m;
+	for(auto &i: anagram){
+		m[i]++;
+	}
+	int count = m.size();
+
+	// vector<int> v;
+
+	int i = 0, j = 0, ans = 0;
+	while(j < s.size()){
+		// calculations
+		if(m.find(s[j]) != m.end()){
+			m[s[j]]--;
+			if(m[s[j]] == 0) count--;
+		}
+
+		if(j - i + 1 < k ) j++;
+
+		else if(j - i + 1 == k){
+			// take answer from calculations
+			if(count == 0) {
+				ans++;
+				// v.push_back(i);
+			}
+
+			if(m.find(s[i]) != m.end()){
+				m[s[i]]++;
+				if(m[s[i]] == 1) count++;
+			}
+			//slide the window
+			i++; j++;
+		}
+	}
+	cout<<ans;
+	// for(auto i : v){
+	// 	cout << i << " ";
+	// }
+
+
+	return 0;
+}