Submission #1330654

#	Time	Username	Problem	Language	Result	Execution time	Memory
1330654		herominhsteve	Sum Zero (RMI20_sumzero)	C++20	61 / 100	295 ms	24556 KiB

sumzero

#include <bits/stdc++.h>
#define el '\n'
#define FNAME "SUMZERO"
#define allof(x) x.begin(),x.end()
#define allof1(x) x.begin()+1,x.end()
#define mset(x,n) memset(x,(n),sizeof(x))
using namespace std;
const long long MOD = (long long) 1e9 + 7;
template<class X,class Y> bool minimize(X &a,Y b){ if (a>b) {a=b; return true;} return false;}
template<class X,class Y> bool maximize(X &a,Y b){ if (a<b) {a=b; return true;} return false;}

void setup(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    if (fopen(FNAME".inp","r")){
        freopen(FNAME".inp","r",stdin);
        freopen(FNAME".out","w",stdout);
    }
}

const int MAXN = 400000 + 5;
const int K = 5;              

int n, q;
int goArr[MAXN];
int up[MAXN][K];  
pair<int,int> queries[MAXN];  

void init(){
    cin>>n;
    for (int i = 0; i <= n; i++) {
        goArr[i] = -1;
        for (int k = 0; k < K; k++) up[i][k] = -1;
    }
    unordered_map<long long,int> last;
    last.reserve((size_t)n * 2 + 10);
    last.max_load_factor(0.7f);

    long long sum = 0;
    last[0] = 0;

    for (int i = 1; i <= n; i++) {
        int x; cin>>x;
        sum += x;

        unordered_map<long long,int>::iterator it = last.find(sum);
        if (it != last.end()){
            goArr[it->second] = i;
        }
        last[sum] = i;
    }

    cin>>q;
    for (int i = 0; i < q; i++) {
        cin>>queries[i].first>>queries[i].second;
    }

    int mn = n + 1;
    for (int pos = n; pos >= 0; pos--) {
        if (goArr[pos] != -1) mn = min(mn, goArr[pos]);
        if (mn <= n) up[pos][0] = mn;
        else up[pos][0] = -1;
    }

    for (int k = 1; k < K; k++) {
        for (int pos = 0; pos <= n; pos++) {
            int x = pos;
            for (int t = 0; t < 16; t++) {
                if (x == -1) break;
                x = up[x][k - 1];
            }
            up[pos][k] = x;
        }
    }
}

void sol(){
    for (int i = 0; i < q; i++) {
        int L = queries[i].first;
        int R = queries[i].second;

        int now = L - 1;
        int res = 0;

        for (int k = K - 1; k >= 0; ) {
            int nx = up[now][k];
            if (~nx and nx <= R) {
                now = nx;
                res += (1<<(4 * k));
            } else {
                k--;
            }
        }
        cout<<res<<el;
    }
}

int main(){
    setup();
    init();
    sol();
    return 0;
}

Compilation message (stderr)

sumzero.cpp: In function 'void setup()':
sumzero.cpp:16:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |         freopen(FNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
sumzero.cpp:17:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         freopen(FNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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