EPI (HEAP) Merge multiple sorted arrays.

#include <vector> #include <iostream> #include <queue>using namespace std;/* Write a program that takes a  n input a set of sorted sequences and compute the union of these sequences as a sorted sequence.  For example: [3, 5, 7], [0, 6, 8], [0, 6, +], then the output was [0, 0, 3, 5, 6, 6, 7, 28]*//* this problem can further   be divided into.  1:there is only sorted sets. 2:the number of input sets is more than two.*///time Complexity:o (n), Space O (n) vector<int> mergetwosets (vector&  lt;int>& set_1, vector<int>& set_2) {int m = set_1.size ();  if (M = = 0) return set_2;  int n = set_2.size ();  if (n = = 0) return set_1;  vector<int> Res;  int i = 0, j = 0;    while (I < m && J < N) {if (Set_1[i] <= set_2[j]) {res.push_back (set_1[i++]);    } else {res.push_back (set_2[j++]);  }} while (I < m) {Res.push_back (set_1[i++]);  } while (J < n) {Res.push_back (set_2[j++]); } return res; void PRintvector (vector<int>& Res) {  for (int i = 0; i < res.size (); ++i) {    cout << re S[i] << endl; }}//identical with merging multiple sorted lists. Time Complexity:nlgk (K is the number of input size). Space lgkvector<int> mergemultisets (const vector< vector<int> >& sets) {  struct Iteratorstartandend {    BOOL Operator < (const iteratorstartandend& that) const {  & nbsp;   return *start > *that.start;   }    vector<int>::const_ Iterator start;    vector<int>::const_iterator end; };  priority_queue< Iteratorstartandend, vector<iteratorstartandend> > minheap;  for (const vector<int>& SORTED_ Array:sets) {    if (!sorted_array.empty ())     Minheap.push (iteratorstartandend{ Sorted_array.cbegin (), Sorted_array.cend ()}); }  VECTOR&LT;INT&GT res;  while (!minheap.empty ()) {    Auto Smallest_array = minheap.top ();    Minheap.pop ();    if (smallest_array.start ! = smallest_array.end) {       Res.push_back (*smallest_array.start);      Minheap.push (IteratorStartAndEnd{next (Smallest_array.start), smallest_array.end});   } }  return res;} int main (void) {  vector<int> set_1{0, 15};  vector<int> set_2{2, 3, ten, 12};  VECTOR&LT;INT&G T Set_3{2, 3, 9, 14};//  vector<int> res = mergetwosets (set_1, set_2); //printvector (res);  vector& Lt vector<int> > multisets;  multisets.push_back (set_1);  multisets.push_back (set_2);  Multisets.push_back (set_3);  vector<int> res_1 = mergemultisets (multisets);  printVector (res_1);}

EPI (HEAP) Merge multiple sorted arrays.