生成視窗最大陣列問題
給定一個整形的陣列arr,和一個大小為w的視窗陣列,從最左邊滑到最右邊,視窗每次向右滑動一個位置,
例如:int arr[] = { 4, 3, 5, 4, 3, 3, 6, 7 ,2,4,5,6,8,1,9,10};當視窗大小為3時,
生成的視窗陣列為res[] = { 5, 5, 5, 4, 6, 7, 7, 7, 5, 6, 8, 8, 9, 10};
下面是C++程式碼:
//生成視窗最大值陣列
//例如陣列arr[] = {4,3,5,4,3,3,6,7};
//視窗大小為3時,則生成陣列 help[] = {5,5,5,4,6,7}
//如果陣列長度為n,視窗大小為w,則一共產生n-w+1個視窗的最大值
#include <vector>
#include <deque>
void getMaxWindow(vector<int> &arr,int w,vector<int> &vec)
{//arr為源陣列,w為視窗大小
if (arr.empty() || w < 1 || arr.size() < w)
return ;
deque<int> qMax;
int index = 0;
for (int i = 0; i < arr.size(); i++)
{
while (!qMax.empty() && arr[qMax.back()] <= arr[i])
{
qMax.pop_back();
}
qMax.push_back(i);
if (qMax.front() == i - w)
{
qMax.pop_front();
}
if (i >= w - 1)
{
vec.push_back(arr[qMax.front()]);
}
}
}
int main()
{
int arr[] = { 4, 3, 5, 4, 3, 3, 6, 7 ,2,4,5,6,8,1,9,10};
vector<int> V;
vector<int> Res;
for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++)
V.push_back(arr[i]);
getMaxWindow(V, 3, Res);
for (auto it = Res.begin(); it != Res.end(); it++)
cout << *it << " ";
cout << endl;
return 0;
}