algo_N0.1

#include <iostream>
#include <sstream>
#include <exception>
#include <cmath>
#include <unordered_set>
#include <vector>
#include <unordered_map>
#define pii pair <int, int>
using namespace std;


int main() {
    int n;
    cin >> n;
    unordered_map <int, int> pf = {{0, -1}};
    int cnt = 0;
    vector <int> idx(n);
    vector <pii> ans;
    vector <int> a(n);
    for(int i = 0; i < n; ++i) {
        int el; cin >> el; a[i] = el;
        cnt += el;
        int dst;
        auto it = pf.find(cnt);
        if (it != pf.end()) {
            ans.push_back(pii{pf[cnt] + 1, i});
            pf[cnt] = i;
        }
    }
    for (auto p: ans) {
        cout << p.first << ' ' << p.second << "\n";
    }
}
/*
10
3 4 -7 3 1 3 1 -4 -2 -2
*/