运行时检查失败＃2-变量'ap'周围的堆栈已损坏

Question

I ran into above problem when I ran following little piece of code in visual C++ 2010 Express.

When I used CodeBlocks, inner for loop couldn't be executed completely because of line (A).

Couldn't figure out why. Thanks for help!

int main()
{
    int* ap[10];
    for(int j=0;j<10;j++){
        *(ap+j) = new int[10];
        for(int i=0;i<10;i++){
            *((ap+j)+i) = *(ap+j)+i;//(A)
            **((ap+j)+i) = j * 10 + i;
            cout<<setw(6)<<**((ap+j)+i);
        }
        cout<<endl;
     }
     return 0;
}

Answer 1

This line

*((ap+j)+i) = *(ap+j)+i;//(A)

can be rewritten as

ap[j+i] = ap[j]+i;//(A)

and you can clearly see this can write out-of-bounds when j+i > 10.

You probably meant ap[j][i] or equivalently *(*(ap+j)+i) .