Submission #1142808

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142808		imarn	XOR Sum (info1cup17_xorsum)	C++20	100 / 100	1293 ms	8260 KiB

xorsum

#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("avx2")
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define plx pair<ll,int>
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()
#define vi vector<int>
#define vvi vector<vi>
#define pp pair<ll,int>
#define ub(x,i) upper_bound(all(x),i)-x.begin()
#define lb(x,i) lower_bound(all(x),i)-x.begin()
#define t3 tuple<int,int,int>
using namespace std;
const int mxn=1e6+5;
const int x[31]={1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768,65536,131072,262144,524288,1048576,2097152,4194304,8388608,16777216,33554432,67108864,134217728,268435456,536870912,1073741824};
int a[mxn]{0};
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n;cin>>n;
    int v[n];int rs=0;
    for(int i=0;i<n;i++)cin>>v[i],a[i]=1;
    for(int p=30;p>=1;p--){
        for(int i=0;i<n;i++)v[i]%=x[p];
        sort(v,v+n);ll cnt=0;
        int l=x[p]/2,r=x[p]-1;
        int tl=((l-v[0])%x[p]+x[p])%x[p];
        int tr=((r-v[0])%x[p]+x[p])%x[p];
        int del=0,add=0,cl=0,cr=0;
        for(int i=0;i<n;i++){
            a[i]=1;
            if(v[i]<tl)del+=a[i],cl=i;
            if(v[i]<=tr)add+=a[i],cr=i;
        }
        for(int i=0;i<n;i++){
            if(tl<=tr)cnt+=add-del;
            else cnt+=(n-i)+add-del;
            if(i==n-1)continue;
            a[i]=0;if(cl>=i)del--;if(cr>=i)add--;
            tl += v[i]-v[i+1];tr+=v[i]-v[i+1];
            if(tl>=0)while(cl>=0&&v[cl]>=tl)del-=a[cl],cl--;
            else {
                tl +=x[p];tl%=x[p];del=0,cl=0;
                for(int j=0;j<n;j++)if(v[j]<tl)del+=a[j],cl=j;
            }
            if(tr>=0)while(cr>=0&&v[cr]>tr)add-=a[cr],cr--;
            else {
                tr +=x[p];tr%=x[p];add=0,cr=0;
                for(int j=0;j<n;j++)if(v[j]<=tr)add+=a[j],cr=j;
            }
        }
        if(cnt%2==1)rs+=x[p-1];
    }cout<<rs;
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 21 / 21
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23