Submission #989873

#	Time	Username	Problem	Language	Result	Execution time	Memory
989873		PedroBigMan	Flood (IOI07_flood)	C++17	54 / 100	272 ms	47168 KiB

flood

#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#pragma GCC optimize("Ofast")
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <list>
#include <iomanip>
#include <stdlib.h>
#include <time.h>
#include <cstring>
using namespace std;
typedef int ll;
typedef unsigned long long int ull;
typedef long double ld;
#define REP(i,a,b) for(ll i=(ll) a; i<(ll) b; i++)
#define pb push_back
#define mp make_pair
#define pl pair<ll,ll>
#define ff first
#define ss second
#define whole(x) x.begin(),x.end()
#define DEBUG(i) cout<<"Pedro "<<i<<endl
#define INF 1000000000
#define EPS ((ld)0.00000000001)
#define pi ((ld)3.141592653589793)
#define VV(vvvv,NNNN,xxxx); REP(iiiii,0,NNNN) {vvvv.pb(xxxx);}
ll mod=1000000007;

template<class A=ll> 
void Out(vector<A> a) {REP(i,0,a.size()) {cout<<a[i]<<" ";} cout<<endl;}

template<class A=ll>
void In(vector<A> &a, ll N) {A cur; REP(i,0,N) {cin>>cur; a.pb(cur);}} 

vector<vector<pl> > adj;

void add_edge(ll A, ll B, ll we)
{
    adj[A].pb({B,we}); adj[B].pb({A,we});
}

ll clockwise(ll dir)
{
    if(dir==0) {return 1;}
    if(dir==1) {return 0;}
    if(dir==2) {return 0;}
    if(dir==3) {return 1;}
    return 0;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	cout.precision(20);
	ll N; vector<pl> p; pl cur; cin>>N; REP(i,0,N) {cin>>cur.ff>>cur.ss; p.pb(cur);}
    ll W; cin>>W; vector<vector<pl> > walls(N,vector<pl>()); ll A,B;
    ll outside = -1; ll outside_coord = INF;
    set<ll> xvals, yvals; map<ll,vector<pl> > beg_x, beg_y, end_x, end_y; set<pl> active;
    vector<pl> walls_order;
    REP(w,0,W) 
    {
        cin>>A>>B; A--; B--;
        if(p[A].ff==p[B].ff) 
        {
            if(p[A].ff<outside_coord) {outside_coord=p[A].ff; outside=w;}
            if(p[A].ss>p[B].ss) {swap(A,B);}
            walls[A].pb({0,w}); walls[B].pb({2,w});
            yvals.insert(p[A].ss); yvals.insert(p[B].ss);
            beg_y[p[A].ss].pb({p[A].ff,w}); end_y[p[B].ss].pb({p[B].ff,w});
            walls_order.pb({p[A].ff,w});
        }
        if(p[A].ss==p[B].ss) 
        {
            if(p[A].ff>p[B].ff) {swap(A,B);}
            walls[A].pb({1,w}); walls[B].pb({3,w});
            xvals.insert(p[A].ff); xvals.insert(p[B].ff);
            beg_x[p[A].ff].pb({p[A].ss,w}); end_x[p[B].ff].pb({p[B].ss,w});
        }
    }
    sort(whole(walls_order));
    adj = vector<vector<pl> >(2*W,vector<pl>());
    set<ll>::iterator it; set<pl>::iterator nxtt; ll X, Y, thisW; ll nxtW;
    active.clear(); it=xvals.begin(); 
    while(it!=xvals.end())
    {
        X=*it;
        REP(i,0,end_x[X].size()) {active.erase(end_x[X][i]);}
        REP(i,0,beg_x[X].size()) {active.insert(beg_x[X][i]);}
        REP(i,0,beg_x[X].size())
        {
            thisW = beg_x[X][i].ss; Y = beg_x[X][i].ff;
            nxtt = active.lower_bound({Y+1,0}); if(nxtt!=active.end()) {nxtW = nxtt->ss; add_edge(2*thisW+1,2*nxtW,0);}
            nxtt = active.lower_bound({Y,0}); if(nxtt!=active.begin()) {nxtt--; nxtW = nxtt->ss; add_edge(2*thisW,2*nxtW+1,0);}
        }
        it++;
    }
    active.clear(); it=yvals.begin(); 
    while(it!=yvals.end())
    {
        Y=*it;
        REP(i,0,end_y[Y].size()) {active.erase(end_y[Y][i]);}
        REP(i,0,beg_y[Y].size()) {active.insert(beg_y[Y][i]);}
        REP(i,0,beg_y[Y].size())
        {
            thisW = beg_y[Y][i].ss; X = beg_y[Y][i].ff;
            nxtt = active.lower_bound({X+1,0}); if(nxtt!=active.end()) {nxtW = nxtt->ss; add_edge(2*thisW+1,2*nxtW,0);}
            nxtt = active.lower_bound({X,0}); if(nxtt!=active.begin()) {nxtt--; nxtW = nxtt->ss; add_edge(2*thisW,2*nxtW+1,0);}
        }
        it++;
    }
    REP(i,0,N) {sort(whole(walls[i]));}
    REP(i,0,W) {add_edge(2*i,2*i+1,1);} 
    ll dirA, dirB; ll nodeA, nodeB; ll nxt;
    REP(i,0,N)
    {
        REP(j,0,walls[i].size())
        {
            nxt = j+1; if(nxt==walls[i].size()) {nxt=0;}
            A=walls[i][j].ss; dirA = walls[i][j].ff;
            B = walls[i][nxt].ss; dirB = walls[i][nxt].ff;
            nodeA = 2*A+clockwise(dirA); nodeB = 2*B + 1 - clockwise(dirB);
            adj[nodeA].pb({nodeB,0});
        }
    }
    if(outside==-1)
    {
        cout<<W<<endl;
        REP(i,0,W) {cout<<i+1<<"\n";} 
        return 0;
    }
    vector<ll> d(2*W,INF); vector<bool> pr(2*W,false); priority_queue<pl> q; ll curr;
    REP(i,0,walls_order.size())
    {
        thisW = 2*walls_order[i].ss;
        if(pr[thisW]) {continue;}
        d[thisW]=0; q.push({0,thisW});
        while(!q.empty())
        {
            curr=q.top().ss; q.pop();
            if(pr[curr]) {continue;}
            pr[curr]=true; 
            REP(i,0,adj[curr].size())
            {
                if(d[adj[curr][i].ff]>d[curr]+adj[curr][i].ss)
                {
                    d[adj[curr][i].ff]=d[curr]+adj[curr][i].ss;
                    q.push(mp(-d[adj[curr][i].ff],adj[curr][i].ff));
                }
            }
        }
        break;
    }
    vector<ll> ans; 
    REP(i,0,W) {if(d[2*i]==d[2*i+1]) {ans.pb(i+1);}}
    cout<<ans.size()<<endl; REP(i,0,ans.size()) {cout<<ans[i]<<"\n";}
    return 0;
}

Compilation message (stderr)

flood.cpp:1: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    1 | #pragma GCC optimization ("O3")
      | 
flood.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization ("unroll-loops")
      | 
flood.cpp: In function 'int main()':
flood.cpp:128:30: warning: comparison of integer expressions of different signedness: 'll' {aka 'int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  128 |             nxt = j+1; if(nxt==walls[i].size()) {nxt=0;}
      |                           ~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 3 / 3
• Subtask 5: 0 / 10
• Subtask 6: 3 / 3
• Subtask 7: 3 / 3
• Subtask 8: 3 / 3
• Subtask 9: 3 / 3
• Subtask 10: 9 / 9
• Subtask 11: 0 / 9
• Subtask 12: 0 / 9
• Subtask 13: 0 / 9
• Subtask 14: 0 / 9