Submission #467128

#	Time	Username	Problem	Language	Result	Execution time	Memory
467128		radaiosm7	XORanges (eJOI19_xoranges)	C++98	100 / 100	154 ms	11248 KiB

xoranges

#include <bits/stdc++.h>
using namespace std;
int n, q, i, a, b, quer;
int c[200005];
int seg[2][800020];

void Update(int start=1, int ende=n, int indx=1) {
  if (start == ende) {
    seg[a&1][indx] = b;
    return;
  }

  int mid = (start+ende)/2;
  if (a <= mid) Update(start, mid, 2*indx);
  else Update(mid+1, ende, 2*indx+1);
  seg[a&1][indx] = seg[a&1][2*indx]^seg[a&1][2*indx+1];
}

int Query(int from, int to, int start=1, int ende=n, int indx=1) {
  if (from == start && to == ende) return seg[a&1][indx];
  int mid = (start+ende)/2;
  if (to <= mid) return Query(from, to, start, mid, 2*indx);
  else if (from > mid) return Query(from, to, mid+1, ende, 2*indx+1);
  else return Query(from, mid, start, mid, 2*indx)^Query(mid+1, to, mid+1, ende, 2*indx+1);
}

void Build(int start=1, int ende=n, int indx=1) {
  if (start == ende) {
    seg[start&1][indx] = c[start];
    return;
  }

  int mid = (start+ende)/2;
  Build(start, mid, 2*indx);
  Build(mid+1, ende, 2*indx+1);

  seg[0][indx] = seg[0][2*indx]^seg[0][2*indx+1];
  seg[1][indx] = seg[1][2*indx]^seg[1][2*indx+1];
}

int main() {
  scanf("%d%d", &n, &q);
  for (i=1; i <= n; ++i) scanf("%d", &c[i]);
  Build();

  while (q--) {
    scanf("%d%d%d", &quer, &a, &b);
    if (quer == 1) Update();
    else if ((a&1) != (b&1)) printf("0\n");
    else printf("%d\n", Query(a, b));
  }

  return 0;
}

Compilation message (stderr)

xoranges.cpp: In function 'int main()':
xoranges.cpp:42:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |   scanf("%d%d", &n, &q);
      |   ~~~~~^~~~~~~~~~~~~~~~
xoranges.cpp:43:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |   for (i=1; i <= n; ++i) scanf("%d", &c[i]);
      |                          ~~~~~^~~~~~~~~~~~~
xoranges.cpp:47:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     scanf("%d%d%d", &quer, &a, &b);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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