李大仁博客

This is an algorithm for finding the greatest common divisor of N (1-20) integers (1-200000) using bitwise optimization to reduce the cost of MOD and division operations. It has a time complexity of O(n) and worst case scenario of O(Log2^C * N) where C is the maximum number in the input. This is a problem from the ACM/ICPC competition and is available for reprint with author attribution and source indication.