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我有一個35個插槽的整數數組。我想插入一個值，並且每次插入一個新值時，我都希望第一個值保持尾部，新值成爲頭部。我不能使用鏈表或隊列，我必須使用void函數。我找不出一種算法，但是我想到的所有東西都包含了一個for循環，我只是不知道如何正確實現它。在C++數組中移位元素
ArrayList.cpp
#include <iostream>
#include "ArrayList.h"
using namespace std;
ArrayList::ArrayList() {
capacity = 8;
length = 0;
array = new int[capacity];
}
ArrayList::ArrayList(const ArrayList& other) {
length = other.length;
capacity = other.capacity;
array = new int[other.capacity];
for (int i = 0; i <= capacity; i++)
array[i] = other.array[i];
}
void ArrayList::add(int item) {
if (length <= capacity) {
changeCapacityTo(2 * capacity);
}
length++;
array[length++] = item;
}
void ArrayList::add(int index, int item) {
while (index > capacity || length == capacity) {
capacity *= 2;
}
if (length != 0 && length < index) {
length = index;
}
int temp;
int i;
for (i = 0; i <= length; i++) {
array[index] = item;
temp = array[index];
array[index + 1] = temp;
}
length++;
}
int ArrayList::get(int index) const {
return array[index];
}
void ArrayList::changeCapacityTo(int newCapacity) {
int *newArray = new int[newCapacity];
int numItemsToCopy = length < newCapacity ? length : newCapacity;
for (int i = 0; i < numItemsToCopy; i++)
newArray[i] = array[i];
delete[] array;
array = newArray;
}
testArrayList.cpp
#include <iostream>
#include "ArrayList.h"
using namespace std;
void verifyArrayList(ArrayList arrayList) {
for(int i = 0; i < 1000; ++i) {
int item;
int itemToAdd = 2 * i;
if((item = arrayList.get(i)) != itemToAdd)
cout << "OOPS - Error at index " << i << ": " << item << " should be "
<< itemToAdd << endl;
}
}
void printArrayList(ArrayList arrayList) {
for(int i = 0; i < arrayList.getLength(); ++i) {
int item = arrayList.get(i);
cout << i << ":" << item << endl;
}
}
int main(int argc, char *argv[]) {
ArrayList arrayList;
const int highIndex = 35;
for(int i = highIndex; i > 0; --i) {
int itemToAdd = 2 * i;
arrayList.add(1, itemToAdd);
//cout << "VALUE OF itemToAdd: " << itemToAdd << endl;
//cout << endl;
}
arrayList.add(99);
printArrayList(arrayList);
cout << "#items = " << arrayList.getLength() << endl;
cout << "capacity = " << arrayList.getCapacity() << endl;
arrayList.add(2000, 9999);
cout << "#items = " << arrayList.getLength() << endl;
cout << "capacity = " << arrayList.getCapacity() << endl;
}
ArrayList.h
#ifndef ARRAYLIST_H_
#define ARRAYLIST_H_
#include <iostream>
class ArrayList {
public:
/*
* Initialize list with a capacity of 8
*/
ArrayList();
/*
* Copy constructor
*/
ArrayList(const ArrayList& other);
virtual ~ArrayList() {
std::cout << "Destructing ArrayList at " << array << std::endl;
delete [] array;
array = NULL;
}
/*
* Add item to end of list
* @param item item to add to list
*/
void add(int item);
/*
* Adds item to list, at index, shifting items as necessary and increasing
* capacity of list as necessary. If capacity must increase, it must always
* be a power of 2. Note that if index is beyond capacity, capacity must be
* increased to allow adding the item at that index. Also, length should
* reflect the HIGHEST index (plus one, naturally) at which an item is
* stored, even if lower-indexed slots contain undefined values.
*
* @param item item to add to list
*/
void add(int index, int item);
/*
* Return item at index. For now, we assume index is legal.
* Later we will throw an exception when index is illegal.
* @param index index of item to return
* @return item at index
*/
int get(int index) const;
/*
* Return capacity
* @return capacity
*/
int getCapacity() const {
return capacity;
}
/*
* Return current length
* @return current length
*/
int getLength() const {
return length;
}
private:
int *array;
int length;
int capacity;
/*
* Change capacity to that specified by newCapacity.
* @param newCapacity the new capacity
*/
void changeCapacityTo(int newCapacity);
};
#endif /* ARRAYLIST_H_ */
這裏是世界衛生大會t時的輸出應該是這樣的： CORRECT OUTPUT
這裏是我的輸出如下： MY OUTPUT
新功能
我試圖在反向array第35個值複製，轉讓他們到reverseArray，然後將相反的順序分配回數組。下面的代碼不能做我期望的。
void ArrayList::add(int index, int item) {
while (index > capacity || length == capacity) {
capacity *= 2;
}
if (length != 0 && length < index) {
length = index;
}
int temp;
int i;
for (i = 0; i <= length; i++) {
array[index] = item;
temp = array[index];
array[index + 1] = temp;
}
length++;
if(length > 35) {
int reverseArray[35];
reverse_copy(array, array + 35, reverseArray);
for(int i = 0; i <= 35; i++) {
array[i] = reverseArray[i];
}
}
}
你可以使用std :: swap嗎？ – Incomputable
在數組中插入一個值？引用數組時，頭和尾是什麼意思？ –
請編輯您的問題，幷包含一個[mcve]，其中包含您已編碼的日期，幷包含一些樣本輸入，實際結果和預期結果。 –