Submission #516994

#	Time	Username	Problem	Language	Result	Execution time	Memory
516994		Stickfish	Sum Zero (RMI20_sumzero)	C++17	61 / 100	311 ms	15896 KiB

sumzero

#include <iostream>
#include <map>
#include <vector>
using namespace std;
using ll = long long;

const int MAXN = 100000;
int a[MAXN];
vector<int> redg[MAXN];

signed main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i)
        cin >> a[i];
    map<ll, int> mp;
    mp[0] = -1;
    ll psm = 0;
    for (int i = 0; i < n; ++i) {
        psm += a[i];
        if (mp.find(psm) == mp.end()) {
            a[i] = -2;
        } else {
            a[i] = mp[psm];
        }
        if (i && a[i - 1] > a[i])
            a[i] = a[i - 1];
        if (a[i] >= -1) {
            redg[i].push_back(a[i]);
            for (int j = 1;; ++j) {
                int v = redg[i][j - 1];
                if (v == -1 || j - 1 >= redg[v].size())
                    break;
                redg[i].push_back(redg[v][j - 1]);
            }
        }
        mp[psm] = i;
    }
    int q;
    cin >> q;
    while (q--) {
        int l, r;
        cin >> l >> r;
        --l;
        int v = r - 1;
        int ans = 0;
        int j = 20;
        while (true) {
            if (v < l || j == -1)
                break;
            if (j >= redg[v].size() || redg[v][j] + 1 < l) {
                --j;
            } else {
                ans += (1 << j);
                v = redg[v][j];
            }
        }
        cout << ans << endl;
    }
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:32:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |                 if (v == -1 || j - 1 >= redg[v].size())
      |                                ~~~~~~^~~~~~~~~~~~~~~~~
sumzero.cpp:51:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |             if (j >= redg[v].size() || redg[v][j] + 1 < l) {
      |                 ~~^~~~~~~~~~~~~~~~~

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