Question

这是我的遍历方法：

Result:
 Running test tool.
$ 
command:  "help"
Result:
    |'exec <testname>' or 'exec !<testnum>'
   |0 BQ1
   |1 BS1
   |2 BA1
   |3 BP1'
$ 
command:  "exec !2"
Result:
 |||TEST BA1_ACTIVE
$ 
command:  "exec !0"
Result:
 |||TEST BQ1_ACTIVE
$ 
command:  "help"
Result:
    |'exec <testname>' or 'exec !<testnum>'
   |0 BQ1
   |1 BS1
   |2 BA1
   |3 BP1'
$ 
command:  "exec !1"
Result:
 |||TEST BS1_ACTIVE
$ 
command:  "exec !3"
Result:
 |||TEST BP3_ACTIVE
$ 
command:  "quit"
Result:
 Quitting.

这是我所拥有的输出：

void heapTraversal(){
        for(int i = 0; i<maxsize; i++){
            cout << "Current value is : " << hipa[i] << endl;
            if(hipa[(2*i)+1]){
                cout << "Left child is : " << hipa[(2*i)+1] << endl;
            }
            else{
                cout << "Left child does not exist" << endl;
            }
            if(hipa[(2*i)+2]){
                cout << "Right child is : " << hipa[(2*i)+2] << endl;
            }
            else{
                cout << "Right child does not exist" << endl;
            }

它似乎工作正常但我拥有所有这些我不应该拥有的垃圾值，我无法查明问题。

我怀疑控制结构有问题，我的逻辑是正确的，还是我应该使用if语句？

Answer 1

我通过将for循环参数从maxsize更改为heap_size来修复此问题。 maxsize应该是堆的容量，而heap_size是堆的当前大小。我为好奇的人添加了其余的课堂宣言。

class minHeap{
    int *hipa;
    int maxsize;
    int heap_size;

public:
    minHeap(int size);
    void minHeapbuild(int );

    int root(int i){
        return (i-1)/2;
    }
    int left(int i){
        return (2*i+1);
    }
    int right(int i){
        return (2*i+2);
    }

    int extractRoot();
    void decreaseKey(int i, int newKey);
    void deleteKey(int key);
    void addKey(int key);

    int getRoot(){
        return hipa[0];
    }
}

Answer 2

即使使用＆＃34;修复＆＃34;你在答案中发布了，heap_size >= (maxsize/2)时你会遇到同样的问题。您必须检查计算的左右子索引。更正后的代码：

void heapTraversal(){
    for(int i = 0; i<heap_size; i++){
        cout << "Current value is : " << hipa[i] << endl;
        int left = (2*i)+1;

        if(left < heap_size && hipa[left]){
            cout << "Left child is : " << hipa[left] << endl;
        }
        else{
            cout << "Left child does not exist" << endl;
        }

        int right = left+1;
        if(right < heap_size && hipa[right]){
            cout << "Right child is : " << hipa[right] << endl;
        }
        else{
            cout << "Right child does not exist" << endl;
        }

遍历min-heap时获取垃圾值

2 个答案: