ege_27_dp_WA

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int, int>
#define pb(x) push_back(x)
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}

void cvl(vector <ll> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}


void cvv(vector <vector <int> > &v) {
    for (auto x : v) cv(x);
    cout << "\n";
}

void cvb(vector <bool> v) {
    for (bool x : v) cout << x << ' ';
    cout << "\n";
}

void cvs(vector <string>  v) {
    for (auto a : v) {
        cout << a << "\n";
    }
}

void cvp(vector <pii> a) {
    for (auto p : a) {
        cout << p.first << ' ' << p.second << "\n";
    }
    cout << "\n";
}

#include <fstream>


int main() {
    string data;
    ifstream file("27.txt");
    getline(file, data);
    int N = stoi(data);
    vector <int> a;
    int ans = 0;
    for (int k = 0; k < N; ++k) {
        getline(file, data);
        int x = stoi(data) % 1111;
        a.pb(x);
        if (x == 0) {
            ans++;
        }
    }
    /*int Si = 0, Sj;
    cout << "N = " << N << "\n";
    for (int i = 0; i < N; ++i) {
        Si += a[i];
        Si %= 1111;
        Sj = 0;
        for (int j = 0; j < i; ++j) {
            Sj += a[j];
            Sj %= 1111;
            if (Si == Sj) {
                cout << i << ' ' << j << "\n";
                ans++;
            }
        }
    }
    cout << ans;*/
    cout << "N = " << N << "\n";
    vector <int> pf(N);
    pf[0] = a[0];
    for (int i = 1; i < N; ++i) {
        pf[i] = pf[i - 1] + a[i];
        pf[i] %= 1111;
    }
    vector <vector <int> > cnt(1111, vector <int> (N, 0));
    for (int i = 0; i < N; ++i) {
        cnt[pf[i]][i]++;
    }
    cnt[a[0]][0]=1;
    for (int i = 1; i < N; ++i) {
        for (int j = 0; j < 1111; ++j) {
            if (j == a[i]) {
                cnt[j][i] = cnt[j][i - 1] + 1;
            } else {
                cnt[j][i] = cnt[j][i - 1];
            }
        }
    }
    //int ans = 0;
    if (pf[0] == 0) {
        ans++;
    }
    for (int i = 1; i < N; ++i) {
        int S = pf[i];
        //cout << "S = " << S << "\n";
        int d = (1111 - S) % 1111;
        ans += cnt[d][i-1];
    }
    cout << "ans\n";
    cout << ans;
}