当计算机在我的代码中要求时，当我没有输入数组中存在的键时如何打印 "The key(element) is not present in your array"

Question

假设我输入 {1,3,3,5} 作为我的数组，当要求输入我想知道其索引的键时，我输入 6。如何编辑我的代码以打印“输入的键不在您的数组中”？

我的代码如下：

#include <iostream>

using namespace std;

void linearsearch(int arr[], int n, int key) {
  int i;

  for (i = 0; i < n; i++) {
    if (arr[i] == key) {
      cout << " \nthe index is: " << i;
    }
  }
}

int main() {
  int n;

  cout << "enter the size of your array : ";

  cin >> n;

  int arr[n];

  cout << "\nenter the keys of your array: ";

  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }

  int key;

  cout << "\n enter the key whose index you want to know: ";

  cin >> key;

  linearsearch(arr, n, key);
}

Answer 1

// 你可以在 void 函数中使用一个布尔控制变量，当你找到数字时，你可以将它的值设置为 true 并在循环结束时插入一个 if 语句来检查 bool 变量的值，如果没有执行循环中的 if 语句，则意味着未找到数字并且变量的值为 false，因此它将打印您询问的行 //

#include <iostream>

using namespace std;

void linearsearch(int arr[], int n, int key) {
  int i;
    bool found = false;
  for (i = 0; i < n; i++) {
    if (arr[i] == key) {
      cout << " \nthe index is: " << i;
      found = true;
    }
  }
  if (found == false){
    cout << "The key entered is not in your array." << endl;
  }
}

int main() {
  int n;

  cout << "enter the size of your array : ";

  cin >> n;

  int arr[n];

  cout << "\nenter the keys of your array: ";

  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }

  int key;

  cout << "\n enter the key whose index you want to know: ";

  cin >> key;

  linearsearch(arr, n, key);
}

当计算机在我的代码中要求时，当我没有输入数组中存在的键时如何打印 "The key(element) is not present in your array"

How to print "The key(element) is not present in your array" when I don't enter a key present in my array when asked for by the computer in my code

c++

arrays

visual-c++

linear-search