在线编译器和 VScode Insiders 上的分段错误让我 [Done] exited with code=3221225725

Question

使用用户输入创建矩阵并在其中搜索元素的程序。 在 Online Compiler 和 VScode Insiders 上编译时出现分段错误让我 [Done] 在 1.181 秒内以 code=3221225725 退出。

Online Compiler used.

VScode+MingW也用过。

#include<iostream>

using namespace std;

int main()
{
    int p;
    do 
    {
        int i,j,k,m;
        int a[j];
                
        m=0;
        
        cout<<"Enter The Number Of Elements You Want In Your Array.\n";
        cin>>j;
        
        cout<<"Give Your Input For The Array.\n";
        for(i=0;i<j;i++)
        {
            cin>>a[i];
        }
    
        cout<<endl<<"Your Array Is:\n";
        
        for(i=0;i<j;i++)
        {
            cout<<a[i]<<endl;
        }
        
        cout<<"Enter The Number You Want To Check.\n";
        cin>>k;
        
        for(i=0;i<j;i++)
        {
            if(a[i]==k)
            {
                m=1;
            }
        }
        if(m==1)
        {
            cout<<"You Number "<<k<<" Is Listed.\n";
        }

        else
        {
            cout<<"You Number "<<k<<" Is Not Listed.\n";
        }

        cout<<"If You Want A Re-Run Press 1 Or Else Press Any Other Number.\n";
        cin>>p;
    } 
    while(p==1);
    return 0;
}

Answer 1

int a[j]; 以未初始化的j 执行。另请注意，可变长度数组 (VLA) 不在标准 C++ 中。你应该改用std::vector。

#include<iostream>
#include<vector> // add this to use std::vector

using namespace std;

int main()
{
    int p;
    do 
    {
        int i,j,k,m;
        // delete this
        //int a[j];
                
        m=0;
        
        cout<<"Enter The Number Of Elements You Want In Your Array.\n";
        cin>>j;
        
        // allocate an array *after* reading j
        std::vector<int> a(j);

        cout<<"Give Your Input For The Array.\n";
        for(i=0;i<j;i++)
        {
            cin>>a[i];
        }
    
        cout<<endl<<"Your Array Is:\n";
        
        for(i=0;i<j;i++)
        {
            cout<<a[i]<<endl;
        }
        
        cout<<"Enter The Number You Want To Check.\n";
        cin>>k;
        
        for(i=0;i<j;i++)
        {
            if(a[i]==k)
            {
                m=1;
            }
        }
        if(m==1)
        {
            cout<<"You Number "<<k<<" Is Listed.\n";
        }

        else
        {
            cout<<"You Number "<<k<<" Is Not Listed.\n";
        }

        cout<<"If You Want A Re-Run Press 1 Or Else Press Any Other Number.\n";
        cin>>p;
    } 
    while(p==1);
    return 0;
}