优先级队列 priority queue

#include <iostream>#include <math.h>static int length;static int Heap_Size;inline int Left( int &i ){return 2*i;}inline int Right( int &i ){return 2*i+1;}inline int Parent( int &i ){return floor(i/2);}inline int Heap_Maximum( int *A ){return A[1];}void Max_Heapify( int *A, int i ){int l,r,largest;l = Left(i);r = Right(i);if( l <= Heap_Size && A[l] > A[i] )                   largest = l;elselargest = i;if( r <= Heap_Size && A[r] > A[largest] )            largest = r;if( largest != i ){int temp = A[i];A[i] = A[largest];A[largest] = temp;Max_Heapify( A, largest );}}void Min_Heapify( int *A, int i ){int l,r,smallest;l = Left(i);r = Right(i);if( l <= Heap_Size && A[l] < A[i] )                  smallest = l;elsesmallest = i;if( r <= Heap_Size && A[r] < A[smallest] )        smallest = r;if( smallest != i ){int temp = A[i];A[i] = A[smallest];A[smallest] = temp;Min_Heapify( A, smallest );}}void Build_Max_Heap( int *A ){Heap_Size = length;                                  for( int i = floor(length/2); i >= 1; --i ){Max_Heapify( A, i );}}void Build_Min_Heap( int *A ){Heap_Size = length;                                 for( int i = floor(length/2); i >= 1; --i ){Min_Heapify( A, i );}}int Heap_Extract_Max( int *A ){if( Heap_Size < 1 ){std::cout << " heap underflow " << std::endl;return -1;}int max = A[1];A[1] = A[Heap_Size];Heap_Size--;Max_Heapify( A, 1 );return max;}void Heap_Increase_Key( int *A, int i, int key ){if( key < A[i] ){std::cout << " new key is smaller than current key " << std::endl;return;}A[i] = key;while( i > 1 && A[Parent(i)] < A[i] ){int temp = A[i];A[i] = A[Parent(i)];A[Parent(i)] = temp;i = Parent(i);}}void Max_Heap_Insert( int *A, int key ){Heap_Size++;A[Heap_Size] = -INFINITY;Heap_Increase_Key( A, Heap_Size, key );}void print( int *A, int n ){for( int i = 1; i <= n; i++ ){std::cout << A[i] << " ";}std::cout << std::endl;}int main( int argc, char* argv[] ){std::cout << " input the length of the array: ";std::cin >> length;int *A;A = new int[length+1];for( int i = 1; i < length+1; i++ ){std::cin >> A[i];}Build_Max_Heap(A);print( A, length );int flag = -1;std::cout << " 0. quit " << std::endl;std::cout << " 1. maximum " << std::endl;std::cout << " 2. insert " << std::endl;std::cout << " 3. extract " << std::endl;std::cout << " 4. increase " << std::endl;std::cin >> flag;while( flag != 0 ){switch( flag ) {case 1:{std::cout << Heap_Maximum( A ) << std::endl;break;}case 2:{int key;std::cin >> key;Max_Heap_Insert( A, key );print( A, Heap_Size );break;}case 3:{std::cout << Heap_Extract_Max( A ) << std::endl;print( A, Heap_Size );break;}case 4:{int i,key;std::cin >> i >> key;Heap_Increase_Key( A, i, key );print( A, Heap_Size );break;}default:break;}std::cout << " 0. quit " << std::endl;std::cout << " 1. maximum " << std::endl;std::cout << " 2. insert " << std::endl;std::cout << " 3. extract " << std::endl;std::cout << " 4. increase " << std::endl;std::cin >> flag;}return 0;}