+std::vector<std::pair<size_t, size_t>> shift_and_frame_private_blocks(const std::vector<std::pair<size_t, size_t>> vec, size_t offset, size_t buff_size) {
+ std::vector<std::pair<size_t, size_t>> result;
+ for(auto block: vec) {
+ auto new_block = std::make_pair(std::min(std::max((size_t)0, block.first-offset), buff_size),
+ std::min(std::max((size_t)0, block.second-offset), buff_size));
+ if(new_block.second > 0 && new_block.first < buff_size)
+ result.push_back(new_block);
+ }
+ return result;
+}
+
+std::vector<std::pair<size_t, size_t>> merge_private_blocks(std::vector<std::pair<size_t, size_t>> src, std::vector<std::pair<size_t, size_t>> dst) {
+ std::vector<std::pair<size_t, size_t>> result;
+ unsigned i_src = 0;
+ unsigned i_dst = 0;
+ while(i_src < src.size() && i_dst < dst.size()) {
+ std::pair<size_t, size_t> block;
+ if(src[i_src].second <= dst[i_dst].first) {
+ i_src++;
+ }
+ else if(dst[i_dst].second <= src[i_src].first) {
+ i_dst++;
+ }
+ else { // src.second > dst.first && dst.second > src.first → the blocks are overlapping
+ block = std::make_pair(std::max(src[i_src].first, dst[i_dst].first),
+ std::min(src[i_src].second, dst[i_dst].second));
+ result.push_back(block);
+ if(src[i_src].second < dst[i_dst].second)
+ i_src ++;
+ else
+ i_dst ++;
+ }
+ }
+ return result;
+}
+