int ia, ib;
for (ia = (strlen(a) - 1); ia >= 0; ia--) {
const char iav = a[ia];
+ const int ial = (ia + 1) & 1; // ia last
for (ib = lb - 1; ib >= 0; ib--) {
const char ibv = b[ib];
- const int ial = (ia + 1) & 1; // ia last
const int iac = ia & 1; // ia current
const int ibl = ib + 1; // ib last
// don't need separate "ib current" as it's just ib