Submission #942764

#	Time	Username	Problem	Language	Result	Execution time	Memory
942764		Pannda	Sum Zero (RMI20_sumzero)	C++17	100 / 100	239 ms	19004 KiB

sumzero

#include <bits/stdc++.h>
using namespace std;

struct DSU {
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;

    vector<int> nxt = [&] {
        vector<pair<long long, int>> a(n + 1);
        a[0] = {0, 0};
        for (int i = 0; i < n; i++) {
            int x;
            cin >> x;
            a[i + 1] = { a[i].first + x, i + 1 };
        }
        sort(a.begin(), a.end());
        vector<pair<int, int>> intervals;
        for (int i = 0; i < n; i++) {
            if (a[i].first == a[i + 1].first) {
                intervals.push_back({a[i].second, a[i + 1].second});
            }
        }
        a.clear();
        vector<pair<long long, int>>().swap(a);
        sort(intervals.begin(), intervals.end(), [&](pair<int, int> x, pair<int, int> y) {
            return x.second < y.second;
        });
        vector<int> nxt(n + 1, n + 1);
        int last_l = -1, last_r = -1;
        for (int i = 0; i < intervals.size(); i++) {
            auto [l, r] = intervals[i];
            if (l <= last_l) continue;
            nxt[l] = r;
            last_l = l;
            last_r = r;
        }
        for (int i = n - 1; i >= 0; i--) {
            if (nxt[i] == n + 1) nxt[i] = nxt[i + 1];
        }
        intervals.clear();
        vector<pair<int, int>>().swap(intervals);
        return nxt;
    }();

    int q;
    cin >> q;
    vector<array<int, 3>> queries(q);
    vector<int> ans(q, -1);
    for (int i = 0; i < q; i++) {
        int l, r;
        cin >> l >> r;
        l--;
        queries[i] = {r, l, i};
    }
    sort(queries.begin(), queries.end());

    vector<int> f(n + 1, 0);
    auto fix = [&](auto self, int i, int r) -> void {
        if (nxt[i] > r) return;
        f[i] = max(f[i], 1);
        self(self, nxt[i], r);
        f[i] += f[nxt[i]];
        if (nxt[nxt[i]] <= r) nxt[i] = nxt[nxt[i]];
    };

    auto get = [&](int i, int r) {
        fix(fix, i, r);
        return f[i];
    };

    for (auto [r, l, i] : queries) {
        ans[i] = get(l, r);
    }

    for (int i = 0; i < q; i++) {
        cout << ans[i] << '\n';
    }
}

Compilation message (stderr)

sumzero.cpp: In lambda function:
sumzero.cpp:36:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         for (int i = 0; i < intervals.size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~
sumzero.cpp:35:26: warning: variable 'last_r' set but not used [-Wunused-but-set-variable]
   35 |         int last_l = -1, last_r = -1;
      |                          ^~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 39 / 39
• Subtask 3: 39 / 39