Add Kumar Karan's string tokenizer program contribution(first) (#60)

* Add Kumar Karan's string tokenizer program contribution

* Added strtok.cpp to README.md and removed file description from strtok.cpp

* renamed strtok.cpp to string-tokeniser.cpp

strings/README.md

@@ -6,6 +6,7 @@
 2. [All subsequences](c-or-cpp/sequence.cpp)
 3. [KMP String Searching](c-or-cpp/kmp.cpp)
 4. [Rabin Karp String Searching](c-or-cpp/rabin-karp.cpp)
+5. [String Tokeniser](c-or-cpp/string-tokeniser.cpp)
 
 
 

strings/c-or-cpp/string-tokeniser.cpp

@@ -0,0 +1,82 @@
+#include <iostream>
+#include <string>
+#include <chrono>
+
+using namespace std;
+
+char* mystrtok(char* s, char d)
+{
+    // Stores the state of string
+    static char* input = NULL;
+
+    // Initialize the input string
+    if (s != NULL)
+        input = s;
+
+    // Case for final token
+    if (input == NULL)
+        return NULL;
+
+    // Stores the extracted string
+    char* result = new char[strlen(input) + 1];
+    int i = 0;
+
+    // Start extracting string and
+    // store it in array
+    for (; input[i] != '\0'; i++) {
+        // If delimeter is not reached
+        // then add the current character
+        // to result[i]
+        if (input[i] != d)
+            result[i] = input[i];
+
+        // Else store the string formed
+        else {
+            result[i] = '\0';
+            input = input + i + 1;	// +1 for adding the delimiter
+            return result;
+        }
+    }
+
+    // Case when loop ends
+	// add '\0' to the last token and return.
+    result[i] = '\0';
+    input = NULL;
+
+    // Return the resultant pointer
+    // to the string
+    return result;
+}
+
+// Driver Code
+int main()
+{
+    // Given string str
+	cout<<"Enter the string.\n";
+	string inputString;
+	char delimiter;
+	getline(cin, inputString);
+	cout<<"Enter the delimiter token character.\n";
+	cin>>delimiter;
+	int n=inputString.length();
+	char str[n+1];
+	strcpy(str, inputString.c_str());
+
+    // Tokenize the first string
+	cout<<"The tokenized string is...\n";
+    char* ptr = mystrtok(str, delimiter);
+
+    // Print current tokenized string
+    cout << ptr << endl;
+
+    // While ptr is not NULL
+    while (ptr != NULL) {
+        // Tokenize the string
+        ptr = mystrtok(NULL, delimiter);
+
+		if(ptr)
+        	// Print the string
+        	cout << ptr << endl;
+    }
+    return 0;
+}

strings/c-or-cpp/strtok.cpp

@@ -0,0 +1,82 @@
+#include <iostream>
+#include <string>
+#include <chrono>
+
+using namespace std;
+
+char* mystrtok(char* s, char d)
+{
+    // Stores the state of string
+    static char* input = NULL;
+
+    // Initialize the input string
+    if (s != NULL)
+        input = s;
+
+    // Case for final token
+    if (input == NULL)
+        return NULL;
+
+    // Stores the extracted string
+    char* result = new char[strlen(input) + 1];
+    int i = 0;
+
+    // Start extracting string and
+    // store it in array
+    for (; input[i] != '\0'; i++) {
+        // If delimeter is not reached
+        // then add the current character
+        // to result[i]
+        if (input[i] != d)
+            result[i] = input[i];
+
+        // Else store the string formed
+        else {
+            result[i] = '\0';
+            input = input + i + 1;	// +1 for adding the delimiter
+            return result;
+        }
+    }
+
+    // Case when loop ends
+	// add '\0' to the last token and return.
+    result[i] = '\0';
+    input = NULL;
+
+    // Return the resultant pointer
+    // to the string
+    return result;
+}
+
+// Driver Code
+int main()
+{
+    // Given string str
+	cout<<"Enter the string.\n";
+	string inputString;
+	char delimiter;
+	getline(cin, inputString);
+	cout<<"Enter the delimiter token character.\n";
+	cin>>delimiter;
+	int n=inputString.length();
+	char str[n+1];
+	strcpy(str, inputString.c_str());
+
+    // Tokenize the first string
+	cout<<"The tokenized string is...\n";
+    char* ptr = mystrtok(str, delimiter);
+
+    // Print current tokenized string
+    cout << ptr << endl;
+
+    // While ptr is not NULL
+    while (ptr != NULL) {
+        // Tokenize the string
+        ptr = mystrtok(NULL, delimiter);
+
+		if(ptr)
+        	// Print the string
+        	cout << ptr << endl;
+    }
+    return 0;
+}