add checkSubstring algorithm in c++

Author: João Pedro Moisakis

String/Substring/check_substring.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+bool isSubstr(string a, string b){
+        bool is =0;
+        if(b.find(a) != std::string::npos){
+            is =1;
+        }
+        return is;
+}      
+//check if string a is substring of b
+int main(){
+    string a,b;
+    cin >> a;
+    cin >> b;
+
+    if(isSubstr(a,b)){
+        cout << "yes"<<endl;
+    }else{
+        cout << "no"<<endl;
+    }
+
+
+    return 0;
+}