How delete int* dynamic array?

I get a problem

"free(): invalid pointer
Process finished with exit code 6"

when I am trying to delete dr[1].

Please say why there is the error in current input (str1, str2)?
”’

#include <iostream>

using namespace std;

int64_t myMin(int64_t first, int64_t second) {
    return first > second ? first : second;
}

int main() {
    string str1, str2;
    str1 = "ABRA", str2 = "CADABRA";
    int64_t n1 = static_cast<int64_t>(str1.length()), n2 = static_cast<int64_t>(str2.length());
    int64_t **dp = new int64_t *[n2 + 1];
    for (int i = 0; i <= n2; ++i) {
        dp[i] = new int64_t[n1 + 1];
        dp[i][0] = 0;
        dp[0][i] = 0;
    }
    for (int64_t i = 1; i <= n2; ++i) {
        for (int j = 1; j <= n1; ++j) {
            if (str2[i - 1] == str1[j - 1]) {
                dp[i][j] = dp[i - 1][j - 1] + 1;
            } else {
                dp[i][j] = myMin(dp[i - 1][j], dp[i][j - 1]);
            }
        }
    }
    cout << dp[n2][n1];
    cout << '\n' << n2 << "\t" << n1 << '\n';
    for (int i = n2; i >= 0; --i) {
//  There is no problem with uncommented below line. Why?
//        if (i != 1)
        delete[] dp[i];
    }
    delete[] dp;
    return 0;
}

”’

I use CLion framework.

>Solution :

dp[0][i] = 0;

When n2 > n1, this will write over the array dp[0] as i grows.

Adding a bound-check will fix this problem:

if (i <= n1)
    dp[0][i] = 0;

In addition, I’d strongly recommend to learn how to debug program.