how do i write this question in C++ in an easy way? (follow the formate in the dark picture)

Problem 9 (5 pts): Write a function that takes as input a binary number and converts it to a decimal number. To convert a binary number, the first digit is multiplied by 20, the second digit is multiplied by 21, the third by 2, etc. e.g., 101102 would be: 0x2 1x2 1x22 0x23 1x24 Or 2210 1000011 would be: 1x2 1x2 0x22 0x23 0x24 0x25 1x25 Or 67 10 #include #include using namespace std; string function (string str); int main() { return 0; string function(string str) {