Submission #658721

#	Time	Username	Problem	Language	Result	Execution time	Memory
658721		Banan	XORanges (eJOI19_xoranges)	C++17	100 / 100	146 ms	16072 KiB

xoranges

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define int long long
#define double long double
#define endl '\n'
#define sz(a) (int)a.size()
#define pb push_back
#define fs first
#define sc second
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
int const INF = LONG_LONG_MAX;

int n, q, a[200005], ev[800040], od[800040];

void build(int v, int l, int r, int* tree,int parity)
{
    if(l==r)
    {
        if((l&1)==parity){tree[v]=a[l];}else{tree[v]=0;}
    }
    else
    {
        int mid=(l+r)/2;
        build(2*v, l, mid, tree, parity);
        build(2*v+1, mid+1, r, tree, parity);
        tree[v]=(tree[2*v]^tree[2*v+1]);
    }
}

void update(int v, int l, int r, int* tree, int pos)
{
    if(l==r)
    {
        tree[v]=a[l];
    }
    else
    {
        int mid=(l+r)/2;
        if(mid>=pos)
        {
            update(2*v, l, mid, tree, pos);
        }
        else
        {
            update(2*v+1, mid+1, r, tree, pos);
        }
        tree[v]=(tree[2*v]^tree[2*v+1]);
    }
}

int ask(int v, int l, int r, int* tree, int sl, int sr)
{
    if(r<sl || l>sr){return 0;}
    if(l==sl && r==sr)
    {
        return tree[v];
    }
    else
    {
        int mid=(l+r)/2;
        int v1=ask(2*v, l, mid, tree, sl, min(mid, sr));
        int v2=ask(2*v+1, mid+1, r, tree, max(mid+1, sl), sr);
        return v1^v2;
    }
}


void solve()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
        cin>>a[i];

    build(1, 1, n, ev, 0);
    build(1, 1, n, od, 1);

    while(q--)
    {
        int t;
        cin>>t;
        if(t==1)
        {
            int pos, val;
            cin>>pos>>val;
            a[pos]=val;
            if(pos&1)
            {
                update(1, 1, n, od, pos);
            }
            else
            {
                update(1, 1, n, ev, pos);
            }
        }
        if(t==2)
        {
            int l, r;
            cin>>l>>r;
            if((r-l+1)&1)
            {
                if(l&1)
                {
                    cout<<ask(1, 1, n, od, l, r)<<endl;
                }
                else
                {
                    cout<<ask(1, 1, n, ev, l, r)<<endl;
                }
            }
            else
            {
                cout<<0<<endl;
            }
        }
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int tc=1;
    //cin>>tc;
    while(tc--)
    {
        solve();
    }
    return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 25 / 25
• Subtask 4: 20 / 20
• Subtask 5: 25 / 25