Submission #861943

#	Time	Username	Problem	Language	Result	Execution time	Memory
861943		imarn	Sum Zero (RMI20_sumzero)	C++14	0 / 100	4 ms	2652 KiB

sumzero

#include<bits/stdc++.h>
//#include "insects.h"
#define f first
#define s second
#define pb push_back
#define pii pair<int,int>
#define ll long long
using namespace std;
const int N=4e5+5;
int pr[N][20]{0};
unordered_map<ll,int>dp;
int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);
    int n;cin>>n;int a[n+1];
    for(int i=1;i<=n;i++)cin>>a[i];
    int sum=0;for(int i=0;i<=n;i++)pr[i][0]=i;
    int id=0;
    dp[0]=0;
    for(int i=1;i<=n;i++){
        sum+=a[i];
        if(dp.find(sum)!=dp.end()){
            while(id<=dp[sum]){
                pr[id++][0]=i;
            }dp[sum]=0;
        }dp[sum]=i;
    }
    for(int j=1;j<20;j++)for(int i=0;i<=n;i++)pr[i][j]=pr[pr[i][j-1]][j-1];
    int q;cin>>q;
    while(q--){
        int st,ed;cin>>st>>ed;st--;
        int l=0,r=n;
        while(l<r){
            int m=(l+r)>>1;
            int x=m;int i=0;
            int cur=st;
            while(x>0){
                if(x&1)cur=pr[cur][i];
                i++;x>>=1;
            }
            if(cur>=ed)r=m;
            else l=m+1;
        }int cur=0;int i=0,x=l;
        while(x>0){
            if(x&1)cur=pr[cur][i];
            i++;x>>=1;
        }
        if(cur==ed)cout<<l<<"\n";
        else cout<<l-1<<"\n";
    }
}

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