Submission #1338094

#	Time	Username	Problem	Language	Result	Execution time	Memory
1338094		nathan4690	Sum Zero (RMI20_sumzero)	C++20	100 / 100	220 ms	12860 KiB

sumzero

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define f1(i,n) for(int i=1;i<=n;i++)
#define __file_name ""
using namespace std;
const ll maxn=4e5+5, inf=1e18;

int n, a[maxn], dep[maxn], par[maxn], jmp[maxn], occ[maxn];
ll pfs[maxn];
bool has[maxn];
map<ll, int> mp;

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if(fopen(__file_name ".inp", "r")){
        freopen(__file_name ".inp", "r", stdin);
        freopen(__file_name ".out", "w", stdout);
    }
    // code here
    cin >> n;
    ll sf = 0;
    f1(i,n) {
        cin >> a[i];
        sf += a[i];
        pfs[i] = sf;
    }
    sort(pfs, pfs+n+1);
    int sz = unique(pfs, pfs+n+1) - pfs;
    sf = 0;
    f1(i,n){
        sf += a[i];
        has[i] |= has[i-1];
        int idx = lower_bound(pfs, pfs+sz+1, sf) - pfs;
        if(occ[idx] || sf == 0){
            has[i] = 1;
            par[i] = occ[idx];
        }
        par[i] = max(par[i], par[i-1]);
        occ[idx] = i;
    }
//    f1(i,n) cout << has[i] << ' ';
//    cout << '\n';
//    f1(i,n) cout << par[i] << ' ';
//    cout << '\n';
    f1(u,n){
        dep[u] = dep[par[u]] + 1;
        int p = par[u];
        if(dep[p] - dep[jmp[p]] == dep[jmp[p]] - dep[jmp[jmp[p]]]){
            jmp[u] = jmp[jmp[p]];
        }else{
            jmp[u] = p;
        }
    }
    int q; cin >> q;
    while(q--){
        int l, r; cin >> l >> r;
        int u = r, pre;
//        cout << "QUERY: " << l << ' ' << r << '\n';
        while(u >= l){
            pre = u;
//            cout << "GOTO: " << u << '\n';
//            u = par[u];
            if(jmp[u] < l) u = par[u];
            else u = jmp[u];
        }
        int ans = dep[r] - dep[pre];
        if(has[pre] && par[pre] + 1 >= l) ans++;
        cout << ans << '\n';
    }
    return 0;
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:18:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         freopen(__file_name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sumzero.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen(__file_name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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