addition about strings

[wxy_3]

Hi;
i have a problem about that i have two long strings of non-negative integers and i wanna denote adddition.How should i do this?

[abhimanipal]

What do you mean when you say "denote addition" ?
Check out strtok(), atoi() you may find it useful to extract numbers from the string

[sourabhtripathi]

Differential equations of addition (DEA) are of the following form:

(x+y)+((x+a)+(y+b))=c;

where x and y are n-bit unknown variables and a, b and c are known variables. The symbols + and denote addition modulo 2n and bitwise exclusive-or respectively. The above equation is denoted by (a,b,c).

Let a set S = {(ai,bi,ci) | i is an integer less than k} denote a system of k DEA where k is a polynomial in n. It has been proved that the satisfiability of an arbitrary set of DEA is in the complexity class P when a brute force search requires an exponential time.