ИТМО. Excel

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
//#include <bits/stdc++.h>
#define pii pair <int,int>
using namespace std;
using ll = long long;
using ld = double;
void cv(vector <int> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n\n";
}
int gcd(int a, int b) {
    if (a < b) {
        swap(a, b);
    }

    while (b) {
        a %= b;
        swap(a, b);
    }

    return a;
}

int lcm(int a, int b) {
    return a / gcd(a, b) * b;   //используя форму a * b / gcd(a, b),
}

struct nmb{
    int a,b;
    nmb pls(nmb x){
        int c,d;
        c = lcm(b, x.b);
        d = a * (c / b) + x.a * (c / x.b);
        nmb r = {d, c};
        return r;
    }
};

map <char, int> L;

int nm(string x){
    reverse(x.begin(), x.end());
    int sz = x.size();
    int res = 0;
    for (int i=0;i<sz;++i){
        res += pow(26, i) * L[x[i]];
    }
    return res;
}
vector <vector <nmb> > tb(1130, vector <nmb> (50));

bool chk(nmb x){
    bool r = 0;
    if (x.a == 0) return 1;
    if (x.a < x.b) return 0;
    int dv = x.a / x.b;
    if (x.b * dv == x.a) r = 1;
    return r;
}
int main()
{
    int cnt = 1;
    for (int i = 65; i <= 90;++i){
        char l = i;
        //cout<<"l= "<<l<<' '<<cnt<<'\n';
        L[l] = cnt;
        cnt++;
    }
    //for (auto x: L)cout<<x.first<<' '<<x.second<<'\n';
    tb[1][nm("A")] = {5,1};
    tb[1][nm("B")] = {4,1};
    tb[1][nm("C")] = {3,1};
    tb[1][nm("E")] = {15,1};
    nmb add = {15,-1};
    for (int i = 2; i <= 1024; ++i){
        add.b = 25;
        tb[i][nm("A")] = tb[i-1][nm("A")].pls(add);
         //cout<< tb[i][nm("A")]<<"\n";
    }
    for (int i = 2; i <=1024;++i){
        add.b = 4;
        tb[i][nm("B")] = tb[i-1][nm("B")].pls(add);
        //cout<< tb[i][nm("B")]<<"\n";

    }
    for (int i = 2; i <= 1024; ++i){
        add.b = 40;
        tb[i][nm("C")] = tb[i-1][nm("C")].pls(add);
    }
    int ans=0;
    vector <nmb> S(1030);
    string f = "               ";
    for (int i=2;i<=1024;++i){
        S[i] = tb[i][nm("A")].pls(tb[i][nm("B")]).pls(tb[i][nm("C")]);
        if (chk(S[i])) ans++;
    }
    cout<<ans<<"\n";
}