Submission #1338093

#	Time	Username	Problem	Language	Result	Execution time	Memory
1338093		KhoaDuy	Sum Zero (RMI20_sumzero)	C++20	61 / 100	1073 ms	10708 KiB

sumzero

#include<bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
const int blsz=500,MAXN=4e5+10;
int lift[MAXN+2];
int nxt[MAXN+2];
signed main(){
    if(fopen("input.txt","r")){
        freopen("input.txt","r",stdin);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    int c[n];
    ll sum=0;
    vector<ll> coor;
    coor.reserve(MAXN+1);
    coor.push_back(0);
    for(int i=0;i<n;i++){
        cin >> c[i];
        sum+=c[i];
        coor.push_back(sum);
    }
    sort(coor.begin(),coor.end());
    coor.erase(unique(coor.begin(),coor.end()),coor.end());
    int last[coor.size()];
    for(int i=0;i<coor.size();i++){
        last[i]=n;
    }
    nxt[n]=n+1,nxt[n+1]=n+1;
    for(int l=n-1;l>=0;l--){
        int idx=lower_bound(coor.begin(),coor.end(),sum)-coor.begin();
        nxt[l]=n;
        last[idx]=l;
        sum-=c[l];
        idx=lower_bound(coor.begin(),coor.end(),sum)-coor.begin();
        nxt[l]=last[idx]+1;
    }
    for(int i=n;i>=0;i--){
        nxt[i]=min(nxt[i],nxt[i+1]);
    }
    // for(int i=0;i<=n;i++){
    //     cout << i << ' ' << nxt[i] << endl;
    // }
    for(int i=0;i<=n+1;i++){
        lift[i]=i;
        for(int bruh=0;bruh<blsz;bruh++){
            lift[i]=nxt[lift[i]];
        }
    }
    int q;
    cin >> q;
    while(q--){
        int l,r;
        cin >> l >> r;
        l--,r--;
        int ans=0;
        while(lift[l]<=r+1){
            l=lift[l];
            ans+=blsz;
        }
        while(l<=r){
            if(nxt[l]<=r+1){
                l=nxt[l];
                ans++;
            }
            else{
                break; 
            }
        }
        cout << ans << endl;
    }
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:10:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         freopen("input.txt","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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