cimport cython

from cython.parallel import prange

@cython.boundscheck(False)

@cython.wraparound(False)

cdef void maximum_path_each(int[:,::1] path, float[:,::1] value, int t_y, int t_x, float max_neg_val=-1e9) nogil:

cdef int x

cdef int y

cdef float v_prev

cdef float v_cur

cdef float tmp

cdef int index = t_x - 1

for y in range(t_y):

for x in range(max(0, t_x + y - t_y), min(t_x, y + 1)):

if x == y:

v_cur = max_neg_val

else:

v_cur = value[y-1, x]

if x == 0:

if y == 0:

v_prev = 0.

else:

v_prev = max_neg_val

else:

v_prev = value[y-1, x-1]

value[y, x] += max(v_prev, v_cur)

for y in range(t_y - 1, -1, -1):

path[y, index] = 1

if index != 0 and (index == y or value[y-1, index] < value[y-1, index-1]):

index = index - 1

@cython.boundscheck(False)

@cython.wraparound(False)

cpdef void maximum_path_c(int[:,:,::1] paths, float[:,:,::1] values, int[::1] t_ys, int[::1] t_xs) nogil:

cdef int b = paths.shape[0]

cdef int i

for i in prange(b, nogil=True):

maximum_path_each(paths[i], values[i], t_ys[i], t_xs[i])