pair<size_t, size_t> lowerb(size_t node, size_t L, size_t R, size_t rl, size_t rr, pair<size_t, size_t> minval) {
if (rl <= L and R <= rr) {
auto it = std::lower_bound(segm[node].begin(), segm[node].end(), minval);
if (it == segm[node].end())
return make_pair(SIZE_MAX, SIZE_MAX);
else
return *it;
}
if (R <= rl or rr <= L)
return make_pair(SIZE_MAX, SIZE_MAX);
size_t mid = L + (R - L) / 2;
return min(lowerb(2 * node + 1, L, mid, rl, rr, minval)
,lowerb(2 * node + 2, mid, R, rl, rr, minval));
}
/*
* Blocked Jacobi solver: one iteration step
*/
double relax_jacobi (double *u, double *utmp, unsigned sizex, unsigned sizey)
{
double diff, sum=0.0;
int howmany=omp_get_max_threads();
#pragma omp parallel reduction(+:sum)
{
for (int blockid = 0; blockid < howmany; ++blockid) {
int i_start = lowerb(blockid, howmany, sizex);
int i_end = upperb(blockid, howmany, sizex);
for (int i=max(1, i_start); i<= min(sizex-2, i_end); i++) {
#pragma omp for nowait private(diff)
for (int j=1; j<= sizey-2; j++) {
utmp[i*sizey+j]= 0.25 * ( u[ i*sizey + (j-1) ]+ // left
u[ i*sizey + (j+1) ]+ // right
u[ (i-1)*sizey + j ]+ // top
u[ (i+1)*sizey + j ]); // bottom
diff = utmp[i*sizey+j] - u[i*sizey + j];
sum += diff * diff;
}
}
}
}
return sum;
}
/*
* Blocked Gauss-Seidel solver: one iteration step
*/
double relax_gauss (double *u, unsigned sizex, unsigned sizey)
{
double unew, diff, sum = 0.0;
int howmany = omp_get_max_threads();
int numBlocs = 8;
int blocsProcesats[howmany];
for(int i = 0; i < howmany; ++i) blocsProcesats[i] = 0;
#pragma omp parallel for schedule(static) private(diff,unew) reduction(+: sum)
for(int i = 0; i < howmany; i++){
int ii_start = lowerb(i,howmany,sizex);
int ii_end = upperb(i,howmany,sizex);
for (int j = 0; j < numBlocs; j++){
int jj_start = lowerb(j,numBlocs,sizey);
int jj_end = upperb(j,numBlocs,sizey);
if(i > 0){
while(blocsProcesats[i-1]<=j){
#pragma omp flush
}
}
for(int ii = max(1,ii_start); ii<= min(sizex-2, ii_end); ii++){
for(int jj= max(1,jj_start); jj<= min(sizey-2, jj_end); jj++){
unew = 0.25* (u[ii * sizey + (jj-1)] + // left
u[ii * sizey + (jj+1)] + // right
u[(ii-1) * sizey + jj] + // top
u[(ii+1) * sizey + jj]); // bottom
diff = unew - u[ii * sizey + jj];
sum+= diff*diff;
u[ii*sizey + jj] = unew;
}
}
++blocsProcesats[i];
#pragma omp flush
}
}
return sum;
}
int main() {
std::iostream::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
size_t n, q;
cin >> n >> q;
for (size_t i = 1; i != n; ++i)
graph[input<size_t>() - 1].push_back(i);
dfs(0);
buildseg(0, 0, MAXN);
for (size_t i = 0; i != q; ++i) {
size_t v = input<size_t>() - 1;
cout << lowerb(0, 0, MAXN, times[v].first, times[v].second, make_pair((sizes[v] + 1) / 2, 0)).second + 1 << "\n";
}
return 0;
}
