程序填空题：Build MinHeap

The function is to turn an array `A[]` of `N` elements into a min-heap.

```c++
#define leftchild(i) ( 2*(i)+1 )

void BuildMinHeap( ElementType A[], int N )
{ int i, j, child;
ElementType Tmp;

for ( i = (N-1)/2; i >= 0; i-- ) {
j = i;
for ( Tmp = A[j]; leftchild(j) < N; j = child ) {
child = leftchild(j);
if (@@[child!=N-1 && A[child+1] child ++;
if (@@[Tmp > A[child]](4)) A[j] = A[child];
else break;
}
@@[A[j] = Tmp](4);
}
}
```

**Thanks to DOU Yan from Yanshan University for the correction!**





答案：
第1空：child!=N-1 && A[child+1]
第2空：Tmp > A[child]

第3空：A[j] = Tmp