Submission #446726

#	Time	Username	Problem	Language	Result	Execution time	Memory
446726		fuad27	XORanges (eJOI19_xoranges)	C++14	75 / 100	1089 ms	3972 KiB

xoranges

#include<bits/stdc++.h>
using namespace std;
#define pass true
int main () {
	int n, q;
	cin >> n >> q;
	vector<int> prefix(n+1, 0);
	vector<int> prefixOdd(n+1, 0);
	vector<int> v(n, 0);
	bool check = false;
	for(int i = 0;i<n;i++) {
		int p;
		cin >> p;
		prefix[i+1] = prefix[i] ^ p;
		if(i%2 == 0) {
			prefixOdd[i+1] = prefixOdd[i] ^ p;
		}
		else {
			prefixOdd[i+1] = prefixOdd[i];
		}
		v[i] = p;	
	}
	while(q--) {
		int k;
		cin >> k;
		if(k == 1) {
			check = true;
			int i, j;
			cin >> i >> j;
			v[i-1] = j;
		}
		else {
			int l, u;
			cin >> l >> u;
			if(!check) {
				if((u - l)%2 == 0) {
					if(l%2 == 1) {
						int ans = prefixOdd[u] ^ prefixOdd[l-1];
						cout<<(ans)<<endl;
					}
					else {
						int ans = prefix[u] ^ prefixOdd[u] ^ prefix[l-1] ^ prefixOdd[l-1];
						cout<<ans<<endl;
					}
				}
				else {
					cout<<0<<endl;
				}
			}
			else {
				int s = 0;
				l--;
				u = min(u, n);
				for(int i = l;i<u;i++) {
					if(((i - l + 1)*(u - i))%2)s^=v[i];
				}
				cout<<s<<endl;
			}
		}
	}
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 25 / 25
• Subtask 4: 20 / 20
• Subtask 5: 0 / 25