C++. Complete the following program so that it determines whether the String str has all unique characters.

HINTS:

• You can use the str.length() to determine the number of characters in the string
• You can add variables to your program, but try to keep them to a minimum

1 #include 4 using namespace std; 6 int main) 8 string str; 9 10 bool is_unique; 11 cin > str; 12 13 //write your solution here 14 15 if(is-unique) 16 17 else 18 19 20 returne; 21 cout