CodeForces 1928F Digital Patterns

洛谷传送门

CF 传送门

为什么我场上被卡常了。

转化题意,将 \(a, b\) 差分,答案为在 \(a, b\) 选出相同长度的不含 \(0\) 的子段方案数。

\(a\) 选出长度为 \(i\) 的不含 \(0\) 的子段方案数为 \(x_i\)\(b\) 选出长度为 \(i\) 的不含 \(0\) 的子段方案数为 \(y_i\)。答案为 \(\sum x_i y_i\)。考虑线段树维护这个东西。

一个 \(a\) 中长度为 \(l\) 的极长子段会给 \(\forall k \in [1, l]\)\(x_k\) 贡献 \(k - l + 1\)\(b\) 同理。\(k + 1\)\(-l\) 是独立的,先考虑 \(-l\) 这部分。也就是要支持 \(x_i \gets x_i + di\)\(y_i \gets y_i + di\)

只考虑修改 \(x\)\(y\) 是对称的。拆式子:\(\sum (x_i + di) y_i = \sum x_i y_i + d \sum i y_i\)。再维护 \(\sum i x_i\)\(\sum i y_i\) 就可以完成 \(\sum x_i y_i\) 的修改。\(\sum i x_i\) 的修改是容易的,考虑 \(\sum i (x_i + i) = \sum i x_i + \sum i^2\),后者显然可以 \(O(1)\) 求的。

还要支持 \(x_i \gets x_i + d\) 或者 \(y_i \gets y_i + d\)。继续拆式子:\(\sum (x_i + d) y_i = \sum x_i y_i + d \sum x_i\)。再维护 \(\sum x_i, \sum y_i\) 即可。

于是线段树每个结点维护 \(5\) 个值:\(\sum x_i y_i, \sum x_i, \sum y_i, \sum i x_i, \sum i y_i\)\(4\) 种懒标记即可。

差分后区间加变成了单点修改。考虑对 \(a, b\) 分别开个 set 维护非 \(0\) 极长连续段。显然单点修改只会加入或删除 \(O(1)\) 个段,讨论下就行了。

时间复杂度 \(O((n + q) \log n)\),但是线段树的常数巨大,实现精细点就能过了。

真的有人会想看 7KB+ 的代码吗?
// Problem: F. Digital Patterns
// Contest: Codeforces - Codeforces Round 924 (Div. 2)
// URL: https://codeforces.com/contest/1928/problem/F
// Memory Limit: 256 MB
// Time Limit: 2000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define pb insert_back
#define fst first
#define scd second
#define mkp make_pair
#define mems(a, x) memset((a), (x), sizeof(a))

using namespace std;
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
typedef long double ldb;
typedef pair<ll, ll> pii;

#define getchar() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 21, stdin), p1 == p2) ? EOF : *p1++)
char buf[1 << 21], *p1 = buf, *p2 = buf;
inline int read() {
    char c = getchar();
    int x = 0;
    bool f = 0;
    for (; !isdigit(c); c = getchar()) f |= (c == '-');
    for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
    return f ? -x : x;
}

const int maxn = 300100;

ll n, m, q, a[maxn], b[maxn];

struct node {
	ll sxy, sx, sy, six, siy;
};

inline node operator + (const node &a, const node &b) {
	node res;
	res.sxy = a.sxy + b.sxy;
	res.sx = a.sx + b.sx;
	res.sy = a.sy + b.sy;
	res.six = a.six + b.six;
	res.siy = a.siy + b.siy;
	return res;
}

inline ll calc1(ll l, ll r) {
	return (l + r) * (r - l + 1) / 2;
}

inline ll calc2(ll n) {
	return n * (n + 1) * (n * 2 + 1) / 6;
}

inline ll calc2(ll l, ll r) {
	return calc2(r) - calc2(l - 1);
}

namespace SGT {
	node a[maxn << 2];
	ll ta1[maxn << 2], ta2[maxn << 2], tb1[maxn << 2], tb2[maxn << 2];
	
	inline void pushup(int x) {
		a[x] = a[x << 1] + a[x << 1 | 1];
	}
	
	inline void pushta1(int x, int l, int r, ll y) {
		node &u = a[x];
		u.sxy += y * u.siy;
		u.sx += y * calc1(l, r);
		u.six += y * calc2(l, r);
		ta1[x] += y;
	}
	
	inline void pushta2(int x, int l, int r, ll y) {
		node &u = a[x];
		u.sxy += y * u.sy;
		u.sx += y * (r - l + 1);
		u.six += y * calc1(l, r);
		ta2[x] += y;
	}
	
	inline void pushtb1(int x, int l, int r, ll y) {
		node &u = a[x];
		u.sxy += y * u.six;
		u.sy += y * calc1(l, r);
		u.siy += y * calc2(l, r);
		tb1[x] += y;
	}
	
	inline void pushtb2(int x, int l, int r, ll y) {
		node &u = a[x];
		u.sxy += y * u.sx;
		u.sy += y * (r - l + 1);
		u.siy += y * calc1(l, r);
		tb2[x] += y;
	}
	
	inline void pushdown(int x, int l, int r) {
		int mid = (l + r) >> 1;
		if (ta1[x]) {
			pushta1(x << 1, l, mid, ta1[x]);
			pushta1(x << 1 | 1, mid + 1, r, ta1[x]);
			ta1[x] = 0;
		}
		if (ta2[x]) {
			pushta2(x << 1, l, mid, ta2[x]);
			pushta2(x << 1 | 1, mid + 1, r, ta2[x]);
			ta2[x] = 0;
		}
		if (tb1[x]) {
			pushtb1(x << 1, l, mid, tb1[x]);
			pushtb1(x << 1 | 1, mid + 1, r, tb1[x]);
			tb1[x] = 0;
		}
		if (tb2[x]) {
			pushtb2(x << 1, l, mid, tb2[x]);
			pushtb2(x << 1 | 1, mid + 1, r, tb2[x]);
			tb2[x] = 0;
		}
	}
	
	void upda1(int rt, int l, int r, int ql, int qr, ll x) {
		if (ql <= l && r <= qr) {
			pushta1(rt, l, r, x);
			return;
		}
		pushdown(rt, l, r);
		int mid = (l + r) >> 1;
		if (ql <= mid) {
			upda1(rt << 1, l, mid, ql, qr, x);
		}
		if (qr > mid) {
			upda1(rt << 1 | 1, mid + 1, r, ql, qr, x);
		}
		pushup(rt);
	}
	
	void upda2(int rt, int l, int r, int ql, int qr, ll x) {
		if (ql <= l && r <= qr) {
			pushta2(rt, l, r, x);
			return;
		}
		pushdown(rt, l, r);
		int mid = (l + r) >> 1;
		if (ql <= mid) {
			upda2(rt << 1, l, mid, ql, qr, x);
		}
		if (qr > mid) {
			upda2(rt << 1 | 1, mid + 1, r, ql, qr, x);
		}
		pushup(rt);
	}
	
	void updb1(int rt, int l, int r, int ql, int qr, ll x) {
		if (ql <= l && r <= qr) {
			pushtb1(rt, l, r, x);
			return;
		}
		pushdown(rt, l, r);
		int mid = (l + r) >> 1;
		if (ql <= mid) {
			updb1(rt << 1, l, mid, ql, qr, x);
		}
		if (qr > mid) {
			updb1(rt << 1 | 1, mid + 1, r, ql, qr, x);
		}
		pushup(rt);
	}
	
	void updb2(int rt, int l, int r, int ql, int qr, ll x) {
		if (ql <= l && r <= qr) {
			pushtb2(rt, l, r, x);
			return;
		}
		pushdown(rt, l, r);
		int mid = (l + r) >> 1;
		if (ql <= mid) {
			updb2(rt << 1, l, mid, ql, qr, x);
		}
		if (qr > mid) {
			updb2(rt << 1 | 1, mid + 1, r, ql, qr, x);
		}
		pushup(rt);
	}
}

inline void updx(int x, int y) {
	SGT::upda1(1, 1, n, 1, x, -y);
	SGT::upda2(1, 1, n, 1, x, y * (x + 1));
}

inline void updy(int x, int y) {
	SGT::updb1(1, 1, n, 1, x, -y);
	SGT::updb2(1, 1, n, 1, x, y * (x + 1));
}

set<int> S, T;
int f[maxn], g[maxn];

inline void addx(int x) {
	auto i = S.lower_bound(x);
	if (i != S.end() && *i == x + 1) {
		updx(f[*i] - *i + 1, -1);
		int l = x, r = f[*i];
		if (i != S.begin() && f[*prev(i)] == x - 1) {
			int p = *prev(i);
			l = p;
			updx(f[p] - p + 1, -1);
			S.erase(prev(i));
		}
		S.erase(i);
		S.insert(l);
		f[l] = r;
		updx(r - l + 1, 1);
	} else if (i != S.begin() && f[*prev(i)] == x - 1) {
		int p = *prev(i);
		S.erase(prev(i));
		int l = p, r = x;
		updx(f[p] - p + 1, -1);
		f[l] = r;
		S.insert(l);
		updx(r - l + 1, 1);
	} else {
		updx(1, 1);
		S.insert(x);
		f[x] = x;
	}
}

inline void delx(int x) {
	auto i = --S.upper_bound(x);
	int p = *i;
	int q = f[p];
	S.erase(i);
	updx(q - p + 1, -1);
	if (p < x) {
		updx(x - p, 1);
		S.insert(p);
		f[p] = x - 1;
	}
	if (x < q) {
		updx(q - x, 1);
		S.insert(x + 1);
		f[x + 1] = q;
	}
}

inline void addy(int x) {
	auto i = T.lower_bound(x);
	if (i != T.end() && *i == x + 1) {
		updy(g[*i] - *i + 1, -1);
		int l = x, r = g[*i];
		if (i != T.begin() && g[*prev(i)] == x - 1) {
			int p = *prev(i);
			l = p;
			updy(g[p] - p + 1, -1);
			T.erase(prev(i));
		}
		T.erase(i);
		T.insert(l);
		g[l] = r;
		updy(r - l + 1, 1);
	} else if (i != T.begin() && g[*prev(i)] == x - 1) {
		int p = *prev(i);
		T.erase(prev(i));
		int l = p, r = x;
		updy(g[p] - p + 1, -1);
		g[l] = r;
		T.insert(l);
		updy(r - l + 1, 1);
	} else {
		updy(1, 1);
		T.insert(x);
		g[x] = x;
	}
}

inline void dely(int x) {
	auto i = --T.upper_bound(x);
	int p = *i;
	int q = g[p];
	T.erase(i);
	updy(q - p + 1, -1);
	if (p < x) {
		updy(x - p, 1);
		T.insert(p);
		g[p] = x - 1;
	}
	if (x < q) {
		updy(q - x, 1);
		T.insert(x + 1);
		g[x + 1] = q;
	}
}

void solve() {
	n = read();
	m = read();
	q = read();
	for (int i = 1; i <= n; ++i) {
		a[i] = read();
	}
	for (int i = 1; i <= m; ++i) {
		b[i] = read();
	}
	for (int i = 1; i < n; ++i) {
		a[i] -= a[i + 1];
	}
	for (int i = 1; i < m; ++i) {
		b[i] -= b[i + 1];
	}
	ll nn = max(n, m) - 1, tn = n, tm = m;
	n = nn;
	for (int i = 1, j = 1; i < tn; i = (++j)) {
		if (!a[i]) {
			continue;
		}
		while (j + 1 < tn && a[j + 1]) {
			++j;
		}
		S.insert(i);
		f[i] = j;
		updx(j - i + 1, 1);
	}
	for (int i = 1, j = 1; i < tm; i = (++j)) {
		if (!b[i]) {
			continue;
		}
		while (j + 1 < tm && b[j + 1]) {
			++j;
		}
		T.insert(i);
		g[i] = j;
		updy(j - i + 1, 1);
	}
	printf("%lld\n", tn * tm + SGT::a[1].sxy);
	while (q--) {
		ll op, l, r, x;
		op = read();
		l = read();
		r = read();
		x = read();
		--l;
		if (op == 1) {
			if (l) {
				ll p = a[l];
				a[l] -= x;
				if (!p && a[l]) {
					addx(l);
				} else if (p && !a[l]) {
					delx(l);
				}
			}
			if (r < tn) {
				ll p = a[r];
				a[r] += x;
				if (!p && a[r]) {
					addx(r);
				} else if (p && !a[r]) {
					delx(r);
				}
			}
		} else {
			if (l) {
				ll p = b[l];
				b[l] -= x;
				if (!p && b[l]) {
					addy(l);
				} else if (p && !b[l]) {
					dely(l);
				}
			}
			if (r < tm) {
				ll p = b[r];
				b[r] += x;
				if (!p && b[r]) {
					addy(r);
				} else if (p && !b[r]) {
					dely(r);
				}
			}
		}
		printf("%lld\n", tn * tm + SGT::a[1].sxy);
	}
}

int main() {
	int T = 1;
	// scanf("%d", &T);
	while (T--) {
		solve();
	}
	return 0;
}

posted @ 2024-02-13 19:16  zltzlt  阅读(17)  评论(0编辑  收藏  举报