C++中堆(优先队列)的应用：make_heap, pop_heap, push_heap, sort_heap, priority_queue

C++中堆的应用：make_heap, pop_heap, push_heap, sort_heap, priority_queue

make_heap, pop_heap, push_heap, sort_heap都是标准算法库里的模板函数，用于将存储在vector/deque 中的元素进行堆操作，对不愿自己写数据结构堆的C++选手来说，这几个算法函数很有用，下面是这几个函数操作vector中元素的例子。详细解释可以参见： http://www.cplusplus.com/reference/algorithm/push_heap/

Demo

```
#include<iostream>
```
```
#include<algorithm>
```
```
#include<vector>
```
```
using namespace std;
```

void print_ivec(vector<int>::iterator begin, vector<int>::iterator end)

```
{
```
```
    for(;begin != end; ++begin)
```
```
        cout << *begin << '\t';
```
```
    cout << endl;
```
```
}
```
```
int main(int argc, char* argv[])
```
```
{
```
```
    int a[] = {1, 12, 15, 20, 30};
```

    vector<int> ivec(a, a + sizeof(a) / sizeof(a[0]));

    print_ivec(ivec.begin(), ivec.end());

    make_heap(ivec.begin(), ivec.end(), greater<int>());

    print_ivec(ivec.begin(), ivec.end());

    pop_heap(ivec.begin(), ivec.end());

```
    ivec.pop_back();
```

    print_ivec(ivec.begin(), ivec.end());

```
    ivec.push_back(99);
```

    push_heap(ivec.begin(), ivec.end());

    print_ivec(ivec.begin(), ivec.end());

    sort_heap(ivec.begin(), ivec.end());

    print_ivec(ivec.begin(), ivec.end());

```
    return 0;
```
```
}
```

Container Adaptors（容器适配器）priority_queue提供了更方便的堆数据结构，操作像queue, stack 一样简单方便，详情参见：

http://www.cplusplus.com/reference/stl/priority_queue/

Demo

```
#include<iostream>
```
```
#include<algorithm>
```
```
#include<queue>
```
```
using namespace std;
```
```
int main(int argc, char* argv[])
```
```
{
```

    priority_queue<int, vector<int>, greater<int>() > pq;

```
    pq.push(676);
```
```
    pq.push(34);
```
```
    pq.push(23);
```
```
    while(!pq.empty())
```
```
    {
```
```
        cout << pq.top() << endl;
```
```
        pq.pop();
```
```
    }
```
```
    return 0;
```
```
}
```

posted @ 2009-12-13 20:24 dskit 阅读(6710) 评论(2) 编辑收藏举报

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