Day8-9

567. Permutation in String/Solution.cs

@@ -0,0 +1,39 @@
+namespace _567._Permutation_in_String;
+
+public class Solution
+{
+    public bool CheckInclusion(string s1, string s2)
+    {
+        int[] letters = new int[26];
+        foreach (char c in s1)
+            letters[c-97]++;
+        int[] buff = new int[26];
+        Array.Copy(letters, buff, letters.Length);
+        for (int i = 0; i <= s2.Length-s1.Length; i++)
+        {
+            if (letters[s2[i]-97] != 0)
+            {
+                Array.Copy(letters, buff, letters.Length);
+                for(int j = i; j < i + s1.Length; j++)
+                {
+                    char ch = s2[j];
+                    buff[ch - 97]--;
+                    if (buff[ch-97] < 0)
+                        break;
+                }
+                bool win = true;
+                for (int bIndex = 0; bIndex < buff.Length; bIndex++)
+                {
+                    if (buff[bIndex] != 0)
+                    {
+                        win = false;
+                        break;
+                    }
+                }
+                if (win)
+                    return true;
+            }
+        }
+        return false;
+    }
+}