Submission #761189

#	Time	Username	Problem	Language	Result	Execution time	Memory
761189		KN200711	XORanges (eJOI19_xoranges)	C++14	100 / 100	108 ms	5156 KiB

xoranges

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

int seg[2][400010];
int arr[200001], gj[200001], gn[200001];
const int MXN = 1e5 + 1;

void build(int lf, int rg, int nd, int ct) {
	if(lf == rg) {
		if(ct == 1) seg[ct][nd] = gj[lf];
		else seg[ct][nd] = gn[lf];
	} else {
		int mid = (lf + rg)/2;
		build(lf, mid, 2*nd+1, ct);
		build(mid+1, rg, 2*nd+2, ct);
		seg[ct][nd] = seg[ct][2*nd+1] ^ seg[ct][2*nd+2];
	}
}

void upd(int lf, int rg, int pos, int nd, int val, int ct) {
	if(lf == rg) {
		seg[ct][nd] = val;
	} else {
		int mid = (lf + rg)/2;
		if(pos <= mid) upd(lf, mid, pos, 2*nd+1, val, ct);
		else upd(mid+1, rg, pos, 2*nd+2, val, ct);
		seg[ct][nd] = seg[ct][2*nd+1] ^ seg[ct][2*nd+2];
	}
}

int qry(int lf, int rg, int clf, int crg, int nd, int ct) {
	if(clf > rg || lf > crg) return 0;
	if(clf <= lf && rg <= crg) return seg[ct][nd];
	int mid = (lf + rg)/2;
	return qry(lf, mid, clf, crg, 2*nd+1, ct) ^ qry(mid+1, rg, clf, crg, 2*nd+2, ct);	
}

int main() {
	int N, Q;
	scanf("%d %d", &N, &Q);
	
	for(int i=0;i<N;i++) {
		scanf("%d", &arr[i]);
		if(i&1) gj[i/2] = arr[i];
		else gn[i/2] = arr[i];
	}
	build(0, MXN, 0, 0);
	build(0, MXN, 0, 1);
	
	while(Q--) {
		int a, b, c;
		scanf("%d %d %d", &a, &b, &c);
		if(a == 2) {
			b--;
			c--;
			if((c - b)&1) printf("0\n");
			else {
				printf("%d\n", qry(0, MXN, b/2, c/2, 0, b&1));
			}
		} else {
			b--;
			upd(0, MXN, b/2, 0, c, b&1);
		}
	}
	return 0;
}

Compilation message (stderr)

xoranges.cpp: In function 'int main()':
xoranges.cpp:40:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |  scanf("%d %d", &N, &Q);
      |  ~~~~~^~~~~~~~~~~~~~~~~
xoranges.cpp:43:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |   scanf("%d", &arr[i]);
      |   ~~~~~^~~~~~~~~~~~~~~
xoranges.cpp:52:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |   scanf("%d %d %d", &a, &b, &c);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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