int main(){
const long long M = 1000000007;
const long long L = 100001;
long t, k; scanf("%ld %ld\n", &t, &k);
std::vector<long long> array(L, 0);
for(long p = 0; p < k; p++){array[p] = 1;}
for(long p = k; p <= L; p++){array[p] = (array[p - 1] + array[p - k]) % M;}
std::vector<long long> cumulative(L, 0);
cumulative[0] = 1; for(long p = 1; p <= L; p++){cumulative[p] = (cumulative[p - 1] + array[p]) % M;}
while(t--){long a, b; scanf("%ld %ld\n", &a, &b); printf("%lld\n", (2 * M + cumulative[b] - cumulative[a - 1]) % M);}
return 0;
}
void spread(void)
{
float min_cost;
int ros_max, ros_base, dir;
int row, col;
int cell_count = 0, ncells = 0;
struct cell_ptrHa *to_cell, *old_to_cell;
struct costHa *pres_cell;
/* initialize using arbitrary value, this value is never used except for debug */
min_cost = 0;
ncells = nrows * ncols;
G_message
("Finding spread time - number of cells visited in percentage ... %3d%%",
0);
pres_cell = (struct costHa *)G_malloc(sizeof(struct costHa));
get_minHa(heap, pres_cell, heap_len);
G_debug(2, "begin spread: cost(%d,%d)=%f", pres_cell->row, pres_cell->col,
pres_cell->min_cost);
G_debug(2,
" heap_len=%ld pres_cell->min_cost=%f time_lag=%d",
heap_len, pres_cell->min_cost, time_lag);
while (heap_len-- > 0 && pres_cell->min_cost < init_time + time_lag + 1.0) {
ros_max = DATA(map_max, pres_cell->row, pres_cell->col);
ros_base = DATA(map_base, pres_cell->row, pres_cell->col);
dir = DATA(map_dir, pres_cell->row, pres_cell->col);
/*Select end cells of links of the present cell */
select_linksB(pres_cell, least / 2, comp_dens);
#ifdef DEBUG
to_cell = front_cell;
while (to_cell != NULL) {
printf("(%d,%d) ", to_cell->row, to_cell->col);
to_cell = to_cell->next;
}
#endif
/*Get a cell in the list each time, and compute culmulative costs
*via the current spread cell*/
to_cell = front_cell;
while (to_cell != NULL) {
/*calculate cumulative costs,
*function returns -1 if detected a barrier */
if (cumulative
(pres_cell, to_cell, ros_max, ros_base, dir,
&min_cost) == -1) {
old_to_cell = to_cell;
to_cell = to_cell->next;
front_cell = to_cell;
G_free(old_to_cell);
continue;
}
G_debug(2, " finish a link: cost(%d,%d)->(%d,%d)=%f",
pres_cell->row, pres_cell->col, to_cell->row,
to_cell->col, min_cost);
/*update the cumulative time/cost */
update(pres_cell, to_cell->row, to_cell->col, to_cell->angle,
min_cost);
old_to_cell = to_cell;
to_cell = to_cell->next;
front_cell = to_cell;
G_free(old_to_cell);
}
/*compute spotting fires */
if (spotting)
spot(pres_cell, dir);
/*mark a visited cell */
DATA(map_visit, pres_cell->row, pres_cell->col) = YES;
#if 0
if (display)
draw_a_cell(pres_cell->row, pres_cell->col,
(int)pres_cell->min_cost);
#endif
cell_count++;
if ((100 * cell_count / ncells) % 2 == 0 &&
(100 * (cell_count + (int)(0.009 * ncells)) / ncells) % 2 == 0) {
G_percent(cell_count, ncells, 2);
}
get_minHa(heap, pres_cell, heap_len);
G_debug(2,
"in while: heap_len=%ld pres_cell->min_cost=%f time_lag=%d",
heap_len, pres_cell->min_cost, time_lag);
} /*end 'while (heap_len-- >0)' */
G_free(pres_cell);
/*Assign min_cost values to un-reached area */
for (row = 0; row < nrows; row++) {
for (col = 0; col < ncols; col++) {
if (!DATA(map_visit, row, col)) {
DATA(map_out, row, col) = (float)BARRIER;
if (x_out)
DATA(map_x_out, row, col) = 0;
if (y_out)
DATA(map_y_out, row, col) = 0;
}
}
}
G_debug(2, "end spread");
} /*end spread () */
