P19918 [GeeksforGeeks] Convert from any base to decimal3736
普及-
题目描述

Given a number N and its base b, convert it to decimal. The base of number can be anything such that all digits can be represented using 0 to 9 and A to Z. Value of A is 10, value of B is 11 and so on.
Example 1:
Input: b = 2, N = 1100
Output: 12
Explaination: It is a binary number whose
decimal equivalent is 12.
Example 2:
Input: b = 16, N = A
Output: 10
Explaination: It's a hexadecimal number whose
decimal equivalent is 10.
Your Task:
You do not need to read input or print anything. Your task is to complete the function decimalEquivalent() which takes N and b as input parameters and returns their decimal equivalent. Otherwise return -1 if N is not possible.
Expected Time Complexity: O(|N|) [|N| means the length of the number N]
Expected Auxiliary Space: O(1)
Constraints:
1 ≤ b ≤ 16
1 ≤ N < decimal equivalent 10^{9}

输入格式

见题面

输出格式

见题面

样例输入
b = 2, N = 1100
样例输出
12