Submission #930180

#	Time	Username	Problem	Language	Result	Execution time	Memory
930180		AmrT	XORanges (eJOI19_xoranges)	C++14	100 / 100	343 ms	17112 KiB

xoranges

#include <bits/stdc++.h>
#define lop(i,a,b) for(ll i = a; i < b; i++)
#define alop(i,v) for(auto &i: v)
#define in(v) for(auto &i: v) cin >> i;
#define ll long long
//#define endl "\n"
#define pb push_back
#define all(v) v.begin(),v.end()
#define mem(dp, x) memset(dp, x, sizeof(dp))
using namespace std;
const ll mod = 1e9 + 7;

struct segtree{
    ll s, e;
    vector<ll> tree;

    void initialize(ll n, vector<ll> arr){
        ll nxt2 = 1 << (__lg(n - 1) + 1);
        s = nxt2 - 1, e = nxt2 * 2 - 2;
        tree.resize(nxt2 * 2 - 1);
        for(int i = 0; i < n; i++)
            tree[i + s] = arr[i];
        for(int i = s - 1; i >= 0; i--)
            tree[i] = tree[i * 2 + 1] ^ tree[i * 2 + 2];
    }
    void update(ll index, ll value){
        index += s;
        tree[index] = value;
        while(index){
            index = (index - !(index % 2) * 2) / 2;
            tree[index] = tree[index * 2 + 1] ^ tree[index * 2 + 2];
        }
    }
    ll get(ll x, ll lx, ll rx, ll l, ll r){
        if(l <= lx && rx <= r) return tree[x];
        else if(rx < l || r < lx) return 0;
        else{
            ll mid = (lx + rx) / 2;
            return get(x * 2 + 1, lx, mid, l, r) ^ get(x * 2 + 2, mid + 1, rx, l, r);
        }
    }
    ll get(ll l, ll r){
        return get(0, s, e, l + s, r + s);
    }
};

int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    ll n, q; cin >> n >> q;
    vector<ll> arr[2];
    for(int i = 0, x; i < n; i++){
        cin >> x;
        arr[i % 2].pb(x);
        arr[!(i % 2)].pb(0);
    }
    segtree a[2]; 
    a[0].initialize(n, arr[0]), a[1].initialize(n, arr[1]);

    while(q--){
        ll t, l, r; cin >> t >> l >> r;
        if(t == 1){
            l--;
            a[l & 1].update(l, r);
        }
        else{
            l--, r--;
            if((r - l + 1) % 2 == 0) 
                cout << 0 << endl;
            else 
                cout << a[(l & 1)].get(l, r) << endl;
        }
    }
    
    return 0;
}

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