What is the mistake I have made in this question(CHRL4)?

#include
#include<stdio.h>
#include
#include
#include<string.h>
#include<math.h>
#include
#include
#include

using namespace std;

int main() {

    long long n, k;
    long long a[100002], pdt[100002];

    cin>>n>>k;


    for ( int i = 1 ; i <= n; i++ ) {
        scanf("%lld", &a[i]);
    }

    long long m, j;

    pdt[1] = a[1];

    for ( int i = 2; i <= n; i++ ) {
        m = -1;
        j = 1;
        while ( ( j <= k ) && ( (i-j) >= 1 ) ) {
            if ( m == -1 ) {
                m = pdt[i-j];
            }
            else if ( m > pdt[i-j] ) {
                m = pdt[i-j];
            }
            j++;
        }
        pdt[i] = ( ( a[i] ) * (m  ) ) % 1000000007;
    }

    cout<<pdt[n];

    return 0;
}

The link to the question:

I agree that I may have to use log() for subtask2, but, I feel that this code should successfully solve atleast subtask1. It isn’t. I have used the same dp approach suggested in the editorial. Can you please let me know where I am going wrong? The sample test case works correctly.

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