Submission #834834

#	Time	Username	Problem	Language	Result	Execution time	Memory
834834		LucaLucaM	Sum Zero (RMI20_sumzero)	C++17	22 / 100	73 ms	27724 KiB

sumzero

#include <bits/stdc++.h>
#warning That's the baby, that's not my baby

typedef long long ll;

using namespace std;

const int NMAX = 4e5;
const int QMAX = 4e5;

vector<pair<int, int>>queries[QMAX + 1];
int l[QMAX + 1], r[QMAX + 1], answer[QMAX + 1];

ll sum[NMAX + 5];
int nxt[NMAX + 5];

const int p2[18] = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072};

vector<int>g[NMAX + 1];
bitset<NMAX + 1>vis;

int st[NMAX + 1];
int top;

void dfs (int u) {
    vis[u] = true;
    st[++top] = u;
//    cout << u << " ";
//    cout << "! ";
//        for (int i = 1; i <= top; i++) {
//            cout << st[i] << ' ';
//        }
//        cout << '\n';

    for (const auto &[pos, index] : queries[u]) {

        int l = 1, r = top;
        while (l < r) {
            int mid = (l + r) / 2;
            if (pos >= st[mid]) {
                r = mid;
            } else {
                l = mid + 1;
            }
        }
//        cout << "? " << st[top] << " - " << pos << '\n';
        answer[index] = top - r;
    }

    for (const auto &v : g[u]) {
        if (!vis[v]) {
            dfs(v);
        }
    }
    top--;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> sum[i];
        sum[i] += sum[i - 1];
    }

    map<int, int>pos;

    nxt[n + 1] = n + 2;

    for (int i = n; i > 0; i--) {
        pos[sum[i]] = i;
        if (!pos.count(sum[i - 1])) {
            nxt[i] = n + 2;
        } else {
            nxt[i] = pos[sum[i - 1]] + 1;
        }
        nxt[i] = min(nxt[i], nxt[i + 1]);
        g[nxt[i]].push_back(i);
//        cout << "   " << nxt[i] << ' ' << i << '\n';
    }

    int q;
    cin >> q;

    int lg2N = __lg(n);

    for (int i = 1; i <= q; i++) {
        cin >> l[i] >> r[i];
        r[i]++;
        queries[l[i]].push_back({r[i], i});
    }

    for (int i = n + 2; i > 0; i--) {
        if (!vis[i]) {
            dfs(i);
        }
    }

    for (int i = 1; i <= q; i++) {
        cout << answer[i] << '\n';
    }

    return 0;
}

Compilation message (stderr)

sumzero.cpp:2:2: warning: #warning That's the baby, that's not my baby [-Wcpp]
    2 | #warning That's the baby, that's not my baby
      |  ^~~~~~~
sumzero.cpp: In function 'int main()':
sumzero.cpp:88:9: warning: unused variable 'lg2N' [-Wunused-variable]
   88 |     int lg2N = __lg(n);
      |         ^~~~

• Subtask 1: 22 / 22
• Subtask 2: 0 / 39
• Subtask 3: 0 / 39