题目（单调队列的应用）：
用一个长度为k的窗口在长度为n的整数数列上从左往右滑动，每次滑动一个单位，求出每次滑动后每个窗口里面所包含的数的最大值。例如：当数列为[1, 3, -1, -3, 5, 3, 6, 7]，窗口大小k=3，可以得出，
| 窗口位置 |
窗口内最大值 |
| [1 3 -1] -3 5 3 6 7 |
3 |
| 1 [3 -1 -3] 5 3 6 7 |
3 |
| 1 3 [-1 -3 5] 3 6 7 |
5 |
| 1 3 -1 [-3 5 3] 6 7 |
5 |
| 1 3 -1 -3 [5 3 6] 7 |
6 |
| 1 3 -1 -3 5 [3 6 7] |
7 |
样例输入：
8 3（分别为n和k）
1 3 -1 -3 5 3 6 7（整数数列）
输出样例：
3 3 5 5 6 7（窗口内最大值）
//单调队列的应用
//author:Mitchell_Donovan
//date:2021.3.22
#include<iostream>
using namespace std;
class arrayQueue {
private:
int size;
int front;
int tail;
int** queue;
public:
arrayQueue(int sizeValue) {
size = sizeValue + 1;
queue = new int*[size];
for (int i = 0; i < size; i++) {
queue[i] = new int[2];
queue[i][0] = queue[i][1] = INT_MAX;
}
front = 0;
tail = 0;
}
~arrayQueue() {
for (int i = 0; i < size; i++) {
delete[]queue[i];
}
delete[]queue;
}
bool push(int rank,int numberValue) {
if (((tail + 1) % size) == front) {
cout << "The queue has been full!" << endl;
return false;
}
tail = (tail + 1) % size;
queue[tail-1][0] = rank;
queue[tail-1][1] = numberValue;
return true;
}
bool poptail() {
if (front == tail) {
cout << "The queue is empty!" << endl;
return false;
}
queue[tail-1][0] = queue[tail-1][1] = INT_MAX;
tail = (size + tail - 1) % size;
return true;
}
bool popfront() {
if (front == tail) {
cout << "The queue is empty!" << endl;
return false;
}
queue[front][0]= queue[front][1] = INT_MAX;
front = (front + 1) % size;
return true;
}
bool getmax(int* array,int arraySize,int testSize) {
for (int i = 0; i < testSize - 1; i++) {
if (array[i] >= queue[(size + tail - 1) % size][1]) {
while (array[i] >= queue[(size + tail - 1) % size][1]) {
poptail();
}
}
push(i, array[i]);
}
for (int i = testSize - 1; i < arraySize; i++) {
if (i - queue[front][0] >= testSize) {
popfront();
}//清空已经过期的元素
if (array[i] >= queue[(size + tail - 1) % size][1]) {
while (array[i] >= queue[(size + tail - 1) % size][1]) {
poptail();
}
}
push(i, array[i]);
cout << queue[front][1] << " ";
}
return true;
}
};
int main() {
int arraySize, testSize;
cout << "Please input the length of array : ";
cin >> arraySize;
cout << "Please input the length of testwindow : ";
cin >> testSize;
int* array = new int[arraySize];
cout << "Please input the value of each number : ";
for (int i = 0; i < arraySize; i++) {
cin >> array[i];
}
arrayQueue test(testSize);
test.getmax(array, arraySize, testSize);
}