ref: 490b46519ceb45220574a4ade95c25eb7d2bb2b4
dir: /libc/adler32.c/
long adler32(char *data) { const int prime = 65521; int i = 0; int a = 0, b = 1; while (i < strlen(data)) { b += data[i]; a += b; i++; } b = b % prime; a = a % prime; return(b << 16 | a); }