Submission #438501

#	Time	Username	Problem	Language	Result	Execution time	Memory
438501		fhvirus	Seats (IOI18_seats)	C++17	100 / 100	1941 ms	145348 KiB

seats

// Knapsack DP is harder than FFT.
#include<bits/stdc++.h>
using namespace std;
typedef long long ll; typedef pair<int,int> pii; typedef pair<ll,ll> pll;
#define ff first
#define ss second
#define pb emplace_back
#define AI(x) begin(x),end(x)
template<class I>bool chmax(I&a,I b){return a<b?(a=b,true):false;}
template<class I>bool chmin(I&a,I b){return b<a?(a=b,true):false;} 
#ifdef OWO
#define debug(args...) SDF(#args, args)
#define OIU(args...) ostream& operator<<(ostream&O,args)
#define LKJ(S,B,E,F) template<class...T>OIU(S<T...>s){O<<B;int c=0;for(auto i:s)O<<(c++?", ":"")<<F;return O<<E;}
LKJ(vector,'[',']',i)LKJ(deque,'[',']',i)LKJ(set,'{','}',i)LKJ(multiset,'{','}',i)LKJ(unordered_set,'{','}',i)LKJ(map,'{','}',i.ff<<':'<<i.ss)LKJ(unordered_map,'{','}',i.ff<<':'<<i.ss)
template<class...T>void SDF(const char* s,T...a){int c=sizeof...(T);if(!c){cerr<<"\033[1;32mvoid\033[0m\n";return;}(cerr<<"\033[1;32m("<<s<<") = (",...,(cerr<<a<<(--c?", ":")\033[0m\n")));}
template<class T,size_t N>OIU(array<T,N>a){return O<<vector<T>(AI(a));}template<class...T>OIU(pair<T...>p){return O<<'('<<p.ff<<','<<p.ss<<')';}template<class...T>OIU(tuple<T...>t){return O<<'(',apply([&O](T...s){int c=0;(...,(O<<(c++?", ":"")<<s));},t),O<<')';}
#else
#pragma GCC optimize("Ofast")
#define debug(...) ((void)0)
#endif

#include "seats.h"

int H, W;
vector<int> R, C; 
vector<vector<int>> A;

vector<int> pre;
bool bld;

struct SGT { 
	struct NOD {
		int val, cnt, tag;
		NOD(): val(0), cnt(0), tag(0) {}
		NOD(int v): val(v), cnt(1), tag(0) {}
		NOD(int v, int c, int t): val(v), cnt(c), tag(t) {}
	};
	int n; vector<NOD> nds;
	void mer(NOD &u, NOD a, NOD b) {
		if(a.val > b.val) swap(a, b);
		u = NOD(a.val, a.cnt, 0);
		if(u.val == b.val) u.cnt += b.cnt;
	}
	void upd(NOD &u, int t){ u.val += t, u.tag += t; }
	void init(int l, int r, int i){
		if(l == r){ nds[i] = NOD(pre[l]); return; }
		int m = (l + r) / 2;
		init(l, m, i*2); init(m + 1, r, i*2+1); 
		mer(nds[i], nds[i*2], nds[i*2+1]);
	}
	void init(int nn) {
		n = nn - 1; nds.resize(n * 4 + 1);
		init(0, n, 1);
	}
	void mod(int l, int r, int i, int ql, int qr, int v) {
		if(ql <= l and r <= qr){ upd(nds[i], v); return; }
		int m = (l + r) / 2;
		NOD &u = nds[i], &a = nds[i * 2], &b = nds[i*2+1];
		upd(a, u.tag), upd(b, u.tag), u.tag = 0;
		if(ql <= m) mod(l, m, i*2, ql, qr, v);
		if(m+1 <= qr) mod(m+1, r, i*2+1, ql, qr, v);
		mer(u, a, b);
	}
	void mod(int ql, int qr, int v) { mod(0, n, 1, ql, qr, v); }
	int que() { return nds[1].cnt; }

	void de(int l, int r, int i){
		NOD &u = nds[i];
		debug(l, r, u.val, u.cnt, u.tag);
		if(l == r) return;
		int m = (l + r) / 2;
		de(l, m, i*2);
		de(m+1, r, i*2+1);
	}
	void de(){ de(0, n, 1); }
} sgt;

inline int eek(int i, int j){ return (i < 0 or j < 0 or i >= H or j >= W ? H * W : A[i][j]); }
void add(int l, int r, int v){
	if(l == r) return;
	if(bld) pre[l] += v, pre[r] -= v;
	else sgt.mod(l, r-1, v);
}
void upd(int i, int j, int v){
	vector<int> tmp({ eek(i, j), eek(i-1, j), eek(i, j-1), eek(i-1, j-1) });
	sort(AI(tmp));
	add(tmp[0], tmp[1], v);
	add(tmp[2], tmp[3], v);
}

void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
	::H = H, ::W = W;
	::R = R, ::C = C;
	A.assign(H, vector<int>(W, 0));
	for(int i = 0; i < H * W; ++i) A[R[i]][C[i]] = i;

	pre.assign(H * W + 1, 0); bld = true;
	for(int i = 0; i <= H; ++i) for(int j = 0; j <= W; ++j) upd(i, j, 1); 
	for(int i = 1; i <= H * W; ++i) pre[i] += pre[i-1];
	debug(pre);
	sgt.init(H * W);
	sgt.de();
	bld = false;
}

int swap_seats(int a, int b) {
	debug(a, b);
	for(int d: {0, 1}) for(int e: {0, 1}) upd(R[a] + d, C[a] + e, -1);
	for(int d: {0, 1}) for(int e: {0, 1}) upd(R[b] + d, C[b] + e, -1);
	swap(A[R[a]][C[a]], A[R[b]][C[b]]);
	swap(R[a], R[b]), swap(C[a], C[b]);
	for(int d: {0, 1}) for(int e: {0, 1}) upd(R[a] + d, C[a] + e, 1);
	for(int d: {0, 1}) for(int e: {0, 1}) upd(R[b] + d, C[b] + e, 1); 
	return sgt.que();
}

Compilation message (stderr)

seats.cpp: In member function 'void SGT::de(int, int, int)':
seats.cpp:69:8: warning: unused variable 'u' [-Wunused-variable]
   69 |   NOD &u = nds[i];
      |        ^

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 20 / 20
• Subtask 4: 6 / 6
• Subtask 5: 33 / 33
• Subtask 6: 30 / 30