permutation in string leetcode

Author: ishan.gupta

permutation-in-string.cpp

@@ -0,0 +1,30 @@
+
+using namespace std;
+#include <iostream>
+#include <bits/stdc++.h>
+// remove above lines when running in leetcode. 
+
+class Solution {
+public:
+    bool checkInclusion(string s1, string s2) {
+        int n = s1.size();
+        int m = s2.size();
+        if(n>m) return false;
+        vector<int> s1_v(26,0);
+        vector<int> s2_v(26,0);
+        for(int i=0;i<n;i++){
+            s1_v[s1[i]-'a']++;
+            s2_v[s2[i]-'a']++;
+        }
+        if(s1_v==s2_v) return true;
+
+        for(int i=n;i<m;i++){
+            s2_v[s2[i-n]-'a']--;
+            s2_v[s2[i]-'a']++;
+            if(s1_v==s2_v) return true;
+        }
+        return false;
+    }
+};
+
+// https://leetcode.com/problems/permutation-in-string/