added hash_table

hash_table.cpp

@@ -0,0 +1,25 @@
+// Author: Proma Roy
+// GITHUB: https://github.com/promaroy
+
+// hash table implementation for finding the frequency of each character in a string...
+
+#include<bits/stdc++.h>
+using namespace std;
+int main()
+{
+  string s="hacktoberfest";//string
+  int hash[26]={0};// initializing hash table to store the frequency of each character..
+
+  for(int i=0;i<s.length();i++)// looping through the string..
+  {
+    hash[s[i]-'a']++; // frequency of "a" stored at hash[0], frequency of "b" stored at hash[1] and so on..
+  }
+  for(int i=0;i<26;i++)
+  {
+    if(hash[i]!=0)
+    {
+      cout<<"Frequency of "<<char(i+'a')<<"- "<<hash[i]<<endl;
+    }
+  }
+
+}