09-排序1 排序 (25 分)

给定N个（长整型范围内的）整数，要求输出从小到大排序后的结果。

本题旨在测试各种不同的排序算法在各种数据情况下的表现。各组测试数据特点如下：

• 数据1：只有1个元素；
• 数据2：11个不相同的整数，测试基本正确性；
• 数据3：103个随机整数；
• 数据4：104个随机整数；
• 数据5：105个随机整数；
• 数据6：105个顺序整数；
• 数据7：105个逆序整数；
• 数据8：105个基本有序的整数；
• 数据9：105个随机正整数，每个数字不超过1000。

  输入格式:

  输入第一行给出正整数N（≤10​5​​），随后一行给出N个（长整型范围内的）整数，其间以空格分隔。

  输出格式:

  在一行中输出从小到大排序后的结果，数字间以1个空格分隔，行末不得有多余空格。

  输入样例:

  11
  4 981 10 -17 0 -20 29 50 8 43 -5
  

  输出样例:

  -20 -17 -5 0 4 8 10 29 43 50 981

  #include<cstdio>
  #include<cstdlib>
  const int maxn = 100010;
  
  //插入排序 
  void insertion_sort(int arr[],int n);
  //希尔排序 
  void shell_sort(int arr[],int n);
  void sedgewick_sort(int arr[], int n);
  
  //选择排序 
  void select_sort(int arr[], int n);
  
  //最小堆排序 
  void percdown(int arr[], int n, int i);
  void heap_sort(int arr[], int n);
  
  //冒泡排序 
  void bubble(int arr[], int n);
  
  //快速排序
  void quick(int arr[], int n); 
  void quick_sort(int arr[], int low, int high);
  int partition(int arr[], int low, int high);
  
  //归并排序-循环方式
  void merge_sort_loop(int arr[], int n);
  void msort_loop(int arr[], int low, int high); 
  void merge_loop(int arr[], int low, int mid, int high);
  
  //归并排序--递归方式
  void merge_sort_recursive(int arr[], int n); 
  void msort_recursive(int arr[], int tmp[], int low, int high);
  void merge_recursive(int arr[], int tmp[], int low, int mid, int high);
  
  int main()
  {
      int n;
      int arr[maxn];
      
      scanf("%d",&n);
      for (int i = 0; i < n; i++)
      {
          scanf("%d",&arr[i]);
      }
      
      //Insertion_sort(arr, n);
      //shell_sort(arr, n);
      //sedgewick_sort(arr, n);
      //select_sort(arr, n);
      //heap_sort(arr, n);
      //bubble(arr, n);
      //quick(arr, n);
      //merge_sort_loop(arr, n);
      merge_sort_recursive(arr, n);
  
      
      for (int i = 0; i < n; i++)
      {
          printf("%d",arr[i]);
          if (i < n - 1)
          {
              printf(" ");
          }
      }
      return 0;
  }
  
  void insertion_sort(int arr[],int n)
  {
      for (int i = 0; i < n; i++)
      {
          int j = i;
          int tmp = arr[i]; 
          for (; j > 0 && arr[j - 1] > tmp; j--)
          {
              arr[j] = arr[j - 1];
          }
          arr[j] = tmp;
      }
  }
  
  void shell_sort(int arr[],int n)
  {
      for (int d = n/2; d > 0; d /= 2)
      {
          for (int i = d; i < n; i++)
          {
              int tmp = arr[i];
              int j = i;
              for (; j >= d && arr[j - d]  > tmp; j -= d)
              {
                  arr[j] = arr[j - d];
              }
              arr[j] = tmp;
          }
      }
  }
  
  void sedgewick_sort(int arr[], int n)
  {
      int si = 0;
      int sedgewick[] = {929, 505, 209, 103, 41, 19, 5, 1, 0};
      for (; sedgewick[si] >= n; si++)
      {
          ;
      }
      
      for (; sedgewick[si] > 0; si++)
      {
          int d = sedgewick[si];
          for (int i = d; i < n; i++)
          {
              int tmp = arr[i];
              int j = i;
              for (; j >= d && arr[j - d] > tmp; j -= d)
              {
                  arr[j] = arr[j - d];
              }
              arr[j] = tmp;
          }
      }
  }
  
  void select_sort(int arr[], int n)
  {
      for (int i = 0; i < n - 1; i++)
      {
          int tmp = arr[i];
          int t = i;
          for (int j = i + 1; j < n; j++)
          {
              if (arr[j] < tmp)
              {
                  tmp = arr[j];
                  t = j;
              }
          }
          arr[t] = arr[i];
          arr[i] = tmp;
      }
  }
  
  void heap_sort(int arr[], int n)
  {
      for (int i = (n-2)/2; i >= 0; i--)
      {
          percdown(arr, n, i);
      }
      for (int i = n - 1; i > 0; i--)
      {
          int temp = arr[i];
          arr[i] = arr[0];
          arr[0] = temp;
          percdown(arr, i, 0);
      }
  }
  
  void percdown(int arr[], int n, int i)
  {
      int parent = i;
      int child;
      int x = arr[parent];
      for (; parent * 2 + 1 < n; parent = child)
      {
          child = parent * 2 + 1;
          if (child < n - 1 && arr[child+1] > arr[child])
          {
              child++;
          }
          
          if (x > arr[child])
          {
              break;
          }
          else
          {
              arr[parent] = arr[child];
          }
      }
      arr[parent] = x;
  }
  
  void bubble(int arr[], int n)
  {
      bool swap = true;
      while (swap)
      {
          swap = false;
          for (int i = 0; i < n-1; i++)
          {
              if (arr[i] > arr[i+1])
              {
                  arr[i] += arr[i+1];
                  arr[i+1] = arr[i] - arr[i+1];
                  arr[i] -= arr[i+1];
                  swap = true;
              }
          }
      }
  }
  
  void quick(int arr[], int n)
  {
      quick_sort(arr, 0, n-1);
  }
  
  void quick_sort(int arr[], int low, int high)
  {
      if(low < high)
      {
          int pivotpos = partition(arr,low,high);
          quick_sort(arr,low,pivotpos-1);
          quick_sort(arr,pivotpos+1,high);
      }
  }
  
  int partition(int arr[], int low, int high)
  {
      int tmp = arr[low];
      while(low < high)
      {
          while(low < high && arr[high] >= tmp)
          {
              high--;
          }
          arr[low] = arr[high];
          while(low < high && arr[low] <= tmp)
          {
              low++;
          }
          arr[high] = arr[low];
      }
      arr[low] = tmp;
      return low;
  }
  
  void merge_sort_loop(int arr[], int n)
  {
      msort_loop(arr, 0, n-1);
  }
  
  void msort_loop(int arr[], int low, int high)
  {
      if (low < high)
      {
          int mid = (low + high) / 2;
          msort_loop(arr, low, mid);
          msort_loop(arr, mid + 1, high);
          merge_loop(arr, low, mid, high);
      }
  }
  
  void merge_loop(int arr[], int low, int mid, int high)
  {
      int i,j,k;
      
      int len_left = mid - low + 1;
      int len_right = high - mid ;
      
      int L[len_left];
      int R[len_right];
      
      for (i = 0 ; i < len_left; i++)
      {
          L[i] = arr[low + i];
      }
      for (i = 0; i < len_right; i++)
      {
          R[i] = arr[1 + mid + i];
      }
      
      i = 0;
      j = 0;
      k = low;
      while(i < len_left && j < len_right)
      {
          if (L[i] <= R[j])
          {
              arr[k++] = L[i++];
          }
          else
          {
              arr[k++] = R[j++];
          }
      }
      
      while(i < len_left)
      {
          arr[k++] = L[i++];
      }
      while (j < len_right)
      {
          arr[k++] = R[j++];
      }
  }
  
  void merge_sort_recursive(int arr[], int n)
  {
      int* tmp = (int *)malloc(n * sizeof(int));
      msort_recursive(arr, tmp, 0, n-1);
      free(tmp);
  }
  
  void msort_recursive(int arr[], int tmp[], int low, int high)
  {
      if (low < high)
      {
          int mid = (low + high) / 2;
          msort_recursive(arr, tmp, low, mid);
          msort_recursive(arr, tmp, mid+1, high);
          merge_recursive(arr, tmp, low, mid, high);
      }
  }
  
  void merge_recursive(int arr[], int tmp[], int low, int mid, int high)
  {
      int left = low;
      int right = mid + 1;
      int start = low;
      
      while (left <= mid && right <= high)
      {
          if (arr[left] <= arr[right])
          {
              tmp[start++] = arr[left++];
          }
          else
          {
              tmp[start++] = arr[right++];
          }
      }
      
      while (left <= mid)
      {
          tmp[start++] = arr[left++];
      }
      while(right <= high)
      {
          tmp[start++] = arr[right++];
      }
      
      for (; low <= high; low++)
      {
          arr[low] = tmp[low];
      }
  }