c++的这种报错该怎么修改

Question

c++ 在acwing写题目的时候遇到的这个报错，改了半天，还是一样的报错，这个到底是啥意思啊，该怎么修改

Answer 1

“Devil组”引证GPT后的撰写：

#include <iostream>
using namespace std;
void copy(int a[], int len, int b[]) {
    for (int i = 0; i < len; i++) b[i] = a[i];
}
int main() {
    int n, m, len;
    cin >> n >> m >> len;
    int a[n], b[m];
    for (int i = 0; i < n; i++) cin >> a[i];
    for (int i = 0; i < m; i++) cin >> b[i];
    copy(a, len, b);
    for (int c : b) cout << c << " ";
    return 0;
}