Submission #1142793

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142793		imarn	XOR Sum (info1cup17_xorsum)	C++20	45 / 100	1695 ms	15952 KiB

xorsum

#include<bits/stdc++.h>
#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 ll 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};
ll fw[mxn]{0};
void add(int i,int amt){
    for(;i<mxn;i+=i&-i)fw[i]+=amt;
}
int qr(int i,int rs=0){
    for(;i;i-=i&-i)rs+=fw[i];
    return rs;
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n;cin>>n;
    ll v[n];ll rs=0;
    for(int i=0;i<n;i++)cin>>v[i];
    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;
        ll l=x[p]/2,r=x[p]-1;
        for(int i=0;i<n;i++){
            add(i+1,1);
            ll tl=((l-v[i])%x[p]+x[p])%x[p];
            ll tr=((r-v[i])%x[p]+x[p])%x[p];
            if(tl<=tr){
                cnt+=qr(upper_bound(v,v+n,tr)-v)-qr(lower_bound(v,v+n,tl)-v);
            }
            else {
                cnt+=(i+1)-qr(lower_bound(v,v+n,tl)-v)+qr(upper_bound(v,v+n,tr)-v);
            }
        }
        if(cnt%2==1)rs+=x[p-1];
        for(int i=1;i<=n;i++)fw[i]=0;
    }cout<<rs;
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 38 / 38
• Subtask 5: 0 / 23