Minimum Range Queries- Runtime error

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Problem :Link I applied the sparse table algorithm here, but I'm somehow getting a runtime error in one of the test cases. Also, I tried to see where is it going wrong, and in the code, the first "here" is printing, and the second "here" after the declaration of the minimum_query array(mq) is not running(for the test case which is giving runtime error). So I guess that the problem should be somewhere there?

Code

void solve()
{

    int n, q;
    cin>>n>>q;
    int sz = n+1;
    vector<int> a(sz);
    for(int i=1; i<=n; ++i)
    {
        cin>>a[i];
    }
    **cout<<"here"<<endl;**
    
    //sparse table algorithm
    int mq[sz][sz];

    **cout<<"here"<<endl;**

    for(int i=1; i<=n; ++i)
        mq[i][i]=a[i];
    int log2n = floor(log2(n));
    for(int k=0; k<=log2n; ++k)
    {
        int gap = 1<<k;
        int till = n-gap;
        for(int i=1; i<=till; ++i)
        {
            int u=i;
            int v=u+gap, w=gap/2;
            mq[u][v]=min(mq[u][u+w], mq[u+w+1][v]);
        }
    }

    while(q--)
    {
        int u,v;
        cin>>u>>v;
        int len = v-u;
        if(v==u)
        {
            cout<<mq[u][v]<<endl;
            continue;
        }
        int k = 1<<((int)(log2(len)));
        int ans = min(mq[u][u+k], mq[v-k][v]);
        cout<<ans<<endl;
    }
}