Submission #973268

#	Time	Username	Problem	Language	Result	Execution time	Memory
973268		terracottalite	XORanges (eJOI19_xoranges)	C++14	100 / 100	106 ms	7852 KiB

xoranges

#include <stdio.h>

int fw[2][200005] = { { 0 } };
int n, q;

int query(int r, int op) {
	int ans = 0;
	while (r > 0) {
		ans ^= fw[op][r];
		r -= r & (-r);
	}
	return ans;
}

void update(int p, int v) {
	int op = p&1;
	int av = query(p, op)^query(p-1, op)^v;
	while (p <= n) {
		fw[op][p] ^= av;
		p += p & (-p);
	}
}

int main()
{
	scanf("%d %d", &n, &q);

	for (int i=1;i<=n;i++) {
		int x;
		scanf("%d", &x);
		update(i, x);
	}

	while (q--) {
		int action;
		scanf("%d", &action);

		if (action == 1) {
			int i, v;
			scanf("%d %d", &i, &v);

			update(i, v);
		} else {
			int l, u;
			scanf("%d %d", &l, &u);

			if ((u-l+1)%2 == 0) {
				puts("0");
				continue;
			}

			int op = l%2;

			printf("%d\n", query(u, op)^query(l-1, op));
		}
	}
}

Compilation message (stderr)

xoranges.cpp: In function 'int main()':
xoranges.cpp:26:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |  scanf("%d %d", &n, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~
xoranges.cpp:30:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   scanf("%d", &x);
      |   ~~~~~^~~~~~~~~~
xoranges.cpp:36:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |   scanf("%d", &action);
      |   ~~~~~^~~~~~~~~~~~~~~
xoranges.cpp:40:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |    scanf("%d %d", &i, &v);
      |    ~~~~~^~~~~~~~~~~~~~~~~
xoranges.cpp:45:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |    scanf("%d %d", &l, &u);
      |    ~~~~~^~~~~~~~~~~~~~~~~

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