rotate.c


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#include <stddef.h>

#include "common.h"

/* rotates left */
void rotate(char *base, size_t size, size_t shift)
{
	int dir = 1;
	while (shift) {
		while (2*shift <= size) {
			swap(base, base + dir*shift, shift);
			size -= shift;
			base += shift*dir;
		}
		shift = size - shift;
		base  = dir > 0 ? base + size - shift : base - shift;
		dir  *= -1;
	}
}