Question

我对 new ， delete 和指针的概念相当陌生，所以对于阅读此内容的人来说，解决方案也许是显而易见的，但老实说我很困惑。

我应该有一个初始化为2个元素的数组，但是当用户输入更多数字时，它将使用 new 运算符不断扩展2个元素，直到用户输入＆＃34 -1＆＃34;

虽然我有编码允许数组增长，但是results are disappointing当程序处理数组时返回数组中最小数字与每个其他数字之间的差异。我给出的唯一提示是：＆＃34;当您更改容量时，您不会从原始数组复制到新数组。＆＃34;但是，我不知道该怎么做。< / p>

非常感谢正确方向的推动。

#include <iostream>

using namespace std;

int main(){

int *ptr;   //pointer to array
int capacity = 2;   //capactity of array
int size = 0;       //how many ints recorded in array
ptr = new int[capacity];
int tmp = 0;

int *numArray = new int[capacity];

while (true){
    cout << "Enter a number: ";
    int num;
    cin >> num;
    if (num == -1) break;
    if (size == capacity){
        int *temp = new int[capacity + 2];
        capacity += 2;
        delete[]ptr;
        ptr = temp;
    }
    ptr[size++] = num;
}

int smallest = numArray[0];

// Code to process array and look for smallest number
for (int i = 0; i < capacity; i++){
    if (numArray[i] < smallest){
        smallest = numArray[i];
    }
}

cout << endl << "The smallest number in the array is: " << smallest << endl << endl;

for (int i = 0; i < capacity; i++){
    int difference = numArray[i] - smallest;
    cout << "The difference between " << numArray[i] << " and the smallest number in the array is : " << difference << endl;
}

system("pause");
}

Answer 1

在这段代码中

<?php
 $execJs = "false";
 session_start();
 if (isset($_SESSION['variable']) && $_SESSION['variable'] === 0) {
  $execJs = "true";
 }
?>
<script>
var id = 'whatever';
var execJs = "<?php echo $execJs ?>";

if (execJs === 'true') {
  toggle_visibility(id);
}

function toggle_visibility(id) {
    var e = document.getElementById(id);
    if(e.style.display == 'block')
        e.style.display = 'none';
    else
       e.style.display = 'block';
}
</script>

您创建了一个新数组，但不将现有数组内容复制到其中。

在创建数组后立即添加以下行

if (size == capacity){
    int *temp = new int[capacity + 2];
    capacity += 2;
    delete[]ptr;
    ptr = temp;
}

进行计算时，您将在数组中输入值。

或者查看for (int i = 0; i < capacity ; ++i) temp[i] = ptr[i];

处理使用new运算符创建的数组的问题

1 个答案: