C++程序中cin读取nosearch时异常退出，ignore/clear无效求助

核心错误 #

你的代码中动态数组的分配方式完全错误：

int *arr = new int(tenn*10); // 错误：仅分配1个int，初始值为tenn*10

正确的数组分配应该使用方括号，用于指定数组元素数量：

int *arr = new int[tenn*10]; // 正确：分配tenn*10个int元素的数组

为什么会导致输入崩溃 #

这种错误会引发内存越界访问的未定义行为：后续的数组填充、排序、输出循环都在读写超出单个int的内存区域，这会破坏程序的栈结构或标准输入流的内部状态，最终导致cin >> nosearch执行时程序直接终止。

额外建议 #

使用动态数组后记得在程序结束前释放内存，避免内存泄漏：

delete[] arr; // 放在main函数末尾

原代码（错误片段标记） #

#include <iostream>
#include <stdlib.h>
#include <ctime>
#include "search.hpp" //a function called sarch is here, program quits before sarch is called. 

using namespace std;

int main () {
    srand(time(0));
    int tenn;
    int minrange;
    int maxrange;
    cout << "Enter the number of integers: ";
    cin >> tenn;
    cout << endl << "Enter the lower limit: ";
    cin >> minrange;
    cout << endl << "Enter the upper limit: ";
    cin >> maxrange;

    // 此处为错误的数组分配
    int *arr = new int(tenn*10);

    for (int i = 0; i < tenn*10; i++){
        *(arr+i) = (rand() % maxrange) + minrange;
    }
    cout << "list, unsorted: " << endl;

    for (int i = 0; i < tenn*10; i++){
        cout << *(arr+i) << " ";
    }
    cout << endl;
    
    for (int i = 0; i < tenn*10; i++){
       
        int low = i;
        for (int j = i; j < tenn*10; j++){
            if (*(arr+j) < *(arr+low)){
                low = j;
            }
        }
        int temp = *(arr+i);
        *(arr+i) = *(arr+low);
        *(arr+low) = temp;
    }

    cout << "sorted list: " << endl;
    
    for (int i = 0; i < tenn*10; i++){
        cout << *(arr+i) << " ";
    }
    cout << endl;

    int nosearch;
    cout << "Enter the number of values you wish to search for: " << endl;
    //The next cin will fail
    cin >> nosearch;
    
    cout << "v";
//more code here...
}

终端运行原程序情况 #

>./Needle.exe
Enter the number of integers: 2

Enter the lower limit: 0

Enter the upper limit: 10
list, unsorted:
9 4 6 2 4 5 2 9 1 4 7 8 3 4 9 4 6 7 9 9
sorted list:
1 2 2 3 4 4 4 4 4 5 6 6 7 7 8 9 9 9 9 9
Enter the number of values you wish to search for:
3

>

内容的提问来源于stack exchange，提问作者Chickendragon