for(int i = 1; i <= m; ++ i) {
  if(bel[i].empty()) {
    insert(1, 1, k, ed[i]);
    continue;
  }
  insert(1, 1, bel[i][0] - 1, ed[i]);
  for(int j = 1; j < bel[i].size() - 1; ++ j) 
    insert(1, bel[i][j - 1] + 1, bel[i][j + 1] - 1, ed[i]); //！！！！！！区间完全不对
  insert(1, bel[i][bel[i].size() - 1] + 1, k, ed[i]);
        }

估计也没人会犯我这错