Big decimal integer constant warning

warning: this decimal constant is unsigned only in ISO C90

if there is no suffix added to the constant:

C90 compilers will follow the following order to read that constant:

• int
• long int
• unsigned long int

while C99 compilers the following order:

• signed int
• signed long
• signed long long

solution:

1. consult compiler (gcc) documentation
2. add proper suffix (ex. UL)

code snippet:

if((u64)s[i-1]>4294967295UL) {
s[i-1]=0;
}