It is an algorithm for the chinese remainder theorem, using c++ as the language tool.
Chinese Remainder Theorem: The Chinese remainder theorem is a result about congruences in number theory and its generalizations in abstract algebra.
In its most basic form it concerned with determining n, given the remainders generated by division of n by several numbers. For example what is the single lowest number if repeatedly divided by 3 gives a remainder of 2; when divided by 5 gives a remainder of 3; and when divided by 7 gives a remainder of 2?