HackerEarth Special matrix problem solution

In this HackerEarth Special Matrix problem solution, you have an N x M matrix, where 1 to N are rows and 1 to M are columns.

Element at the intersection of ith row and jth column is equal to F(i + j), where F(x) is equal to the number of prime divisors of x. Determine the sum of all the elements of the matrix.

#include "bits/stdc++.h"
#define debug(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
#define time__(d) 
    for ( 
        auto blockTime = make_pair(chrono::high_resolution_clock::now(), true); 
        blockTime.second; 
        debug("%s: %d msn", d, (int)chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - blockTime.first).count()), blockTime.second = false 
    )
#ifdef LOCAL
#include "pprint.hpp"
#endif
#define endl 'n';
#define pb push_back
#define mod 1000000007
#define ll long long int
#define prn(x) cerr<<x<<endl;
#define all(x) x.begin(),x.end()
using namespace std;
#define test_case 1

const int Mx = 2e6+5;
vector<int> v, p;

void solution(){
    int n,m;
    cin>>n>>m;
    assert(n>=1 && n<=1000000);
    assert(m>=1 && m<=1000000);
    if(n<m)
        swap(n,m);
    ll ans=0;
    for(int i=1;i<=n;++i){
        int tot=min(i,m);
        ans += (ll)v[i+1]*(ll)tot;
    }
    int tot=m-1;
    for(int i=2;i<=m;++i){
        ans += (ll)v[n+i]*(ll)tot;
        tot--;
    }
    cout<<ans<<endl;
}

int main(int argc, char *argv[])
{
    #ifdef LOCAL
        freopen("in.txt" , "r" , stdin);
    #else
        ios_base::sync_with_stdio(false);
        cin.tie(NULL); cout.tie(NULL);
    #endif
    p.assign(Mx+5,1);
    v.assign(Mx+5,0);
    p[0]=p[1]=0;
    for(int i=2;i<Mx;++i)
        if(p[i])
            for(int j=i;j<Mx;j+=i){
                v[j]++;
                p[j]=0;
            }
    int t=1;
    if(test_case)
        cin>>t;
    assert(t>=1 && t<=10);
    time__("Solution Time"){
        while(t--){
            solution();
        }
    }

    return 0;
}