CF341D Iahub and Xors

CF341D Iahub and Xors

给定一个 \(n\times n\) 的矩阵，平面异或，求平面异或和 \((n\leq10^3,\ m\leq10^5)\)

树状数组

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这里主要是记录一下板子……qaq

时间复杂度 \(O(m\log^2n)\)

代码

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

typedef long long ll;
const int maxn = 1010;
int n, m, a[maxn][maxn]; ll c[4][maxn][maxn];

void upd(int x, int y, ll val) {
  int p = (x & 1) + ((y & 1) << 1);
  for (int i = x; i <= n; i += i & -i) {
    for (int j = y; j <= n; j += j & -j) {
      c[p][i][j] ^= val;
    }
  }
}

ll query(int x, int y) {
  int p = (x & 1) + ((y & 1) << 1); ll res = 0;
  for (int i = x; i; i &= i - 1) {
    for (int j = y; j; j &= j - 1) {
      res ^= c[p][i][j];
    }
  }
  return res;
}

int main() {
  scanf("%d %d", &n, &m);
  int op, x1, y1, x2, y2; ll x;
  while (m--) {
    scanf("%d %d %d %d %d", &op, &x1, &y1, &x2, &y2);
    if (op == 1) {
      printf("%lld\n", query(x2, y2) ^ query(x1 - 1, y2) ^ query(x2, y1 - 1) ^ query(x1 - 1, y1 - 1));
    } else {
      scanf("%lld", &x);
      upd(x1, y1, x), upd(x2 + 1, y1, x), upd(x1, y2 + 1, x), upd(x2 + 1, y2 + 1, x);
    }
  }
  return 0;
}