Submission #1110473

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110473		Zero_OP	Sum Zero (RMI20_sumzero)	C++14	61 / 100	343 ms	25388 KiB

sumzero

#include <bits/stdc++.h>

using namespace std;

#define rep(i, l, r) for(int i = (l); i < (r); ++i)
#define sz(v) (int)v.size()
#define dbg(x) "[" #x " = " << (x) << "]"
#define all(v) begin(v), end(v)
#define compact(v) v.erase(unique(all(v)), end(v))
#define file(name) if(fopen(name".inp", "r")){ freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }

template<typename T>
    bool minimize(T& a, const T& b){
        if(a > b){
            return a = b, true;
        }
        return false;
    }

template<typename T>
    bool maximize(T& a, const T& b){
        if(a < b){
            return a = b, true;
        }
        return false;
    }

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using vi = vector<int>;
using vl = vector<ll>;

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

    file("task");

    int N;
    cin >> N;
    vector<int> a(N + 1);
    vector<long long> pref(N + 1);
    map<long long, int> last;

    for(int i = 1; i <= N; ++i){
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }

    int L = 5;

    vector<int> pw16(L);
    pw16[0] = 1;
    pw16[1] = 16;
    for(int i = 2; i < L; ++i){
        pw16[i] = pw16[i - 1] * 16;
    }

    const int inf = 1e9;
    vector<vector<int>> lift(L, vector<int>(N + 2, inf));
    for(int i = N; i >= 0; --i){
        //select smallest j such sum [i...j) = 0
        if(i < N) lift[0][i + 1] = (last.find(pref[i]) == last.end() ? inf : last[pref[i]] + 1);
        if(i > 0) last[pref[i]] = i;
    }

    for(int i = N - 1; i >= 1; --i){
        minimize(lift[0][i], lift[0][i + 1]);
    }

    for(int i = 1; i < L; ++i){
        for(int j = 1; j <= N; ++j){
            lift[i][j] = j;
            for(int rep = 0; rep < 16; ++rep){
                if(lift[i][j] == inf) break;
                lift[i][j] = lift[i - 1][lift[i][j]];
            }
        }
    }

    int Q;
    cin >> Q;
    while(Q--){
        int l, r;
        cin >> l >> r;
        ++r;

        int ans = 0;
        for(int i = L - 1; i >= 0; --i){
            while(lift[i][l] <= r){
                ans += pw16[i];
                l = lift[i][l];
            }
        }

        cout << ans << '\n';
    }

    return 0;
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:10:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | #define file(name) if(fopen(name".inp", "r")){ freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sumzero.cpp:40:5: note: in expansion of macro 'file'
   40 |     file("task");
      |     ^~~~
sumzero.cpp:10:88: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | #define file(name) if(fopen(name".inp", "r")){ freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
sumzero.cpp:40:5: note: in expansion of macro 'file'
   40 |     file("task");
      |     ^~~~

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