c语言长整数的和（超过64位）

#include<stdio.h>
#include<string.h>
#include<math.h>
void f(char a[],int aa)
{
    char t;
    int i;
    for(i=0;i<=(aa-1)/2;i++)
    {
        t=a[i];
        a[i]=a[aa-1-i];
        a[aa-1-i]=t;
    }
}
void g(char a[],char b[],char c[])
{
    int k,g,j,i,aa,bb,min,kk,y;
    aa=strlen(a);
    bb=strlen(b);
    k=0;
    g=0;
    if(aa>bb)
    {
        g=1;
        min=bb;
    }
    else if(bb>aa)
    {
        g=2;
        min=aa;