如下:
heapify每次把当前分支的最小的放在top
然后遍历每个“小树”,即可。。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include<stdio.h> 2 #include<string.h> 3 #include<algorithm> 4 using namespace std; 5 const int maxn = 100005; 6 #define LEFT( x ) ((x<<1)+1) 7 #define RIGHT( x ) ((x+1)<<1) 8 #define PARENT( x ) ((x-1)/2)//((x+1)>>1-1) 9 int a[ maxn ]; 10 void heapify( int pos,int n ){ 11 int pos_l,pos_r,tmp; 12 pos_l = LEFT( pos ); 13 pos_r = RIGHT( pos ); 14 tmp = pos; 15 if( pos_l<=n&&a[ pos_l ]<a[ pos ] ){ 16 tmp = pos_l; 17 } 18 if( pos_r<=n&&a[ pos_r ]<a[ tmp ] ){ 19 tmp = pos_r; 20 }//GET THE MIN 21 if( tmp!=pos ){ 22 swap( a[ tmp ],a[ pos ] ); 23 heapify( tmp,n ); 24 } 25 return ; 26 } 27 28 int build_the_min_top( int n ){ 29 for( int i=(int)PARENT( n );i>=0;i-- ){ 30 heapify( i,n ); 31 } 32 return a[ 0 ];//return the min 33 } 34 35 int main(){ 36 int ca; 37 scanf("%d",&ca); 38 for( int t=0;t<ca;t++ ){ 39 int num; 40 scanf("%d",&num); 41 printf("case #%d:\n",t); 42 int n = 0; 43 while( num-- ){ 44 char s[5]; 45 scanf("%s",s); 46 if( s[0]=='B' ){ 47 int tmp; 48 scanf("%d",&tmp); 49 a[ n++ ] = tmp; 50 } 51 else { 52 printf("%d\n",build_the_min_top( n-1 ) ); 53 swap( a[ 0 ],a[ n-1 ] ); 54 n--;//remove the min to the tail 55 } 56 } 57 } 58 return 0; 59 }