/* wrap2.c - circular wrap of pointer offset q, relative to array w */void wrap2(M, q)int M, *q;{       if (*q > M)                *q -= M + 1;          /* when \(*q=M+1\), it wraps around to \(*q=0\) */       if (*q < 0)                *q += M + 1;          /* when \(*q=-1\), it wraps around to \(*q=M\) */}