#ifndef AC_KVEC_H
#define AC_KVEC_H
#include <stdlib.h>
#define kv_roundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
#define kvec_t(type) struct { size_t n, m; type *a; }
#define kv_init(v) ((v).n = (v).m = 0, (v).a = 0)
#define kv_destroy(v) free((v).a)
#define kv_A(v, i) ((v).a[(i)])
#define kv_pop(v) ((v).a[--(v).n])
#define kv_size(v) ((v).n)
#define kv_max(v) ((v).m)
#define kv_clear(v) ((v).n = 0)
#define kv_resize(type, v, s) ((v).m = (s), (v).a = (type*)realloc((v).a, sizeof(type) * (v).m))
#define kv_copy(type, v1, v0) do { \
if ((v1).m < (v0).n) kv_resize(type, v1, (v0).n); \
(v1).n = (v0).n; \
memcpy((v1).a, (v0).a, sizeof(type) * (v0).n); \
} while (0) \
#define kv_push(type, v, x) do { \
if ((v).n == (v).m) { \
(v).m = (v).m? (v).m<<1 : 2; \
(v).a = (type*)realloc((v).a, sizeof(type) * (v).m); \
} \
(v).a[(v).n++] = (x); \
} while (0)
#define kv_pushp(type, v) (((v).n == (v).m)? \
((v).m = ((v).m? (v).m<<1 : 2), \
(v).a = (type*)realloc((v).a, sizeof(type) * (v).m), 0) \
: 0), ((v).a + ((v).n++))
#define kv_a(type, v, i) (((v).m <= (size_t)(i)? \
((v).m = (v).n = (i) + 1, kv_roundup32((v).m), \
(v).a = (type*)realloc((v).a, sizeof(type) * (v).m), 0) \
: (v).n <= (size_t)(i)? (v).n = (i) + 1 \
: 0), (v).a[(i)])
#endif