rt，白嫖的oiwiki上的模板，但是报了段错误，具体是这一行：Htree root = createHuffmanTree(n);

不知道哪里有问题呜呜

#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <cstdlib>
#include <map>
#include <cmath>
#include <unordered_map>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
const int sze = 4e5 + 5;
int n;
int arr[sze];
typedef struct HNode {
  int weight;
  HNode *lchild, *rchild;
} * Htree;
Htree createHuffmanTree(int n) {
  Htree forest[sze];
  Htree root = NULL;
  for (int i = 0; i < n; i++) {
    Htree temp;
    temp = (Htree)malloc(sizeof(HNode));
    temp->weight = arr[i];
    temp->lchild = temp->rchild = NULL;
    forest[i] = temp;
  }

  for (int i = 1; i < n; i++) {  
    int minn = -1, minnSub; 
    for (int j = 0; j < n; j++) {
      if (forest[j] != NULL && minn == -1) {
        minn = j;
        continue;
      }
      if (forest[j] != NULL) {
        minnSub = j;
        break;
      }
    }

    for (int j = minnSub; j < n; j++) { 
      if (forest[j] != NULL) {
        if (forest[j]->weight < forest[minn]->weight) {
          minnSub = minn;
          minn = j;
        } else if (forest[j]->weight < forest[minnSub]->weight) {
          minnSub = j;
        }
      }
    }
    root = (Htree)malloc(sizeof(HNode));
    root->weight = forest[minn]->weight + forest[minnSub]->weight;
    root->lchild = forest[minn];
    root->rchild = forest[minnSub];

    forest[minn] = root;     
    forest[minnSub] = NULL;  
  }
}

int getWPL(Htree root, int len) {  
  if (root == NULL)
    return 0;
  else {
    if (root->lchild == NULL && root->rchild == NULL) 
      return root->weight * len;
    else {
      int left = getWPL(root->lchild, len + 1);
      int right = getWPL(root->rchild, len + 1);
      return left + right;
    }
  }
}

void solve(){
    cin >> n;
    for(int i = 0; i < n; i++)
        cin >> arr[i];
	Htree root = createHuffmanTree(n);
    cout << getWPL(root, 0) << '\n';
    free(root);
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T;
    cin >> T;
    while (T--)
        solve();
    return 0;
}