제출 #259809

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
259809		MarcoMeijer	Building Skyscrapers (CEOI19_skyscrapers)	C++14	61 / 100	3201 ms	190712 KiB

skyscrapers

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

// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e9
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()

// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }

// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi," ",x.se);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }

//===================//
//  Added libraries  //
//===================//

//===================//
//end added libraries//
//===================//

void program();
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    program();
}


//===================//
//   begin program   //
//===================//

const int MX = 7e5;

int dx4[]={-1,0,1,0};
int dy4[]={0,1,0,-1};
int dx8[]={ 0, 1, 1, 1, 0,-1,-1,-1};
int dy8[]={ 1, 1, 0,-1,-1,-1, 0, 1};

int n, t, m;
int R[MX], C[MX];
bitset<MX> visited;
map<ii,int> posID;
map<ii,int> f;
set<ii> build;
set<ii> out;
set<int> pq;
vi ans;
int outside;

int p[MX], r[MX], sets;
void buildDSU(int dsuSize) {
    RE(i,dsuSize) p[i]=i, r[i]=0;
    sets = dsuSize;
}
int getSet(int i) {return i==p[i]?i:p[i]=getSet(p[i]);}
bool isSameSet(int i, int j) {return getSet(i)==getSet(j);}
void unionSet(int i, int j) {
    if(!isSameSet(i,j)) {
        i=p[i], j=p[j];
        sets--;
        if(r[i] > r[j]) {
            p[j] = i;
        } else {
            p[i] = j;
            if(r[i] == r[j]) r[j]++;
        }
    }
}
bool isEmpty(int i) {
    return isSameSet(i, outside);
}

bool hasEmptyConnected(ii p) {
    int x=p.fi, y=p.se;
    RE(d,4) {
        int nx=x+dx4[d];
        int ny=y+dy4[d];
        if(out.count({nx,ny}))
            return 1;
    }
   return 0;
}
bool canDestroy(ii p) {
    if(!hasEmptyConnected(p)) return 0;
    int x=p.fi, y=p.se;

    int start=0;
    bool isBuild[8];
    RE(d,8) {
        int nx=x+dx8[d];
        int ny=y+dy8[d];
        isBuild[d] = build.count({nx,ny});
        if(isBuild[d]) {
            start = d;
        }
    }
    RE(d,4) {
        int cd=d*2;
        int nd=(cd+2)%8;
        if(isBuild[cd] && isBuild[nd])
            isBuild[(cd+1)%8]=1;
    }

    set<int> curRegions;
    bool last=1;
    int pos=(start+1)%8;
    while(pos!=start) {
        int nx=x+dx8[pos];
        int ny=y+dy8[pos];
        if(last && !isBuild[pos]) {
            int reg = getSet(posID[{nx,ny}]);
            if(curRegions.count(reg)) return 0;
            curRegions.insert(reg);
        }
        last = isBuild[pos];
        pos=(pos+1)%8;
    }

    return 1;
}
void updateBuild(ii p) {
    if(canDestroy(p)) {
        pq.insert(f[p]);
    } else {
        pq.erase(f[p]);
    }
}
void addOutside(ii p) {
    if(out.count(p)) return;
    bool foundBuild=0;
    int x=p.fi, y=p.se;
    RE(d,8) {
        int nx=x+dx8[d];
        int ny=y+dy8[d];
        if(build.count({nx,ny})) {
            foundBuild=1;
            break;
        }
    }
    if(!foundBuild) return;

    out.insert(p);
    RE(d,4) {
        int nx=x+dx4[d];
        int ny=y+dy4[d];
        if(!build.count({nx,ny}))
            addOutside({nx,ny});
    }
    RE(d,8) {
        int nx=x+dx8[d];
        int ny=y+dy8[d];
        if(build.count({nx,ny}))
            updateBuild({nx,ny});
    }
}

void dfsPossible(ii p) {
    if(!build.count(p)) return;
    if(visited[f[p]]) return;
    visited[f[p]] = 1;
    int x=p.fi, y=p.se;
    RE(d,8) {
        int nx=x+dx8[d];
        int ny=y+dy8[d];
        dfsPossible({nx,ny});
    }
}
bool isPossible() {
    visited.reset();
    dfsPossible({R[1],C[1]});
    RE1(i,n) if(!visited[i]) return 0;
    return 1;
}
void addPossible(ii p) {
    if(posID.count(p)) return;
    int res = posID.sz;
    posID[p] = res;
}

void program() {
    IN(n,t);
    RE1(i,n) IN(R[i],C[i]);
    RE1(i,n) build.insert({R[i],C[i]});
    RE1(i,n) f[{R[i],C[i]}]=i;
    RE1(i,n) {
        int x=R[i], y=C[i];
        RE(d,8) {
            int nx=x+dx8[d];
            int ny=y+dy8[d];
            addPossible({nx,ny});
        }
        addPossible({x,y});
    }
    m = posID.sz;

    // create dsu
    buildDSU(m);
    FOR(p,posID) {
        int x = p.fi.fi;
        int y = p.fi.se;
        if(build.count({x,y})) continue;
        RE(d,4) {
            int nx=x+dx4[d];
            int ny=y+dy4[d];
            if(build.count({nx,ny})) continue;
            if(!posID.count({nx,ny})) continue;
            unionSet(p.se, posID[{nx,ny}]);
        }
    }

    // set outside(if there is a solution)
    if(isPossible()) {
        ii start = *build.begin();
        start.fi--;
        outside = posID[start];
        addOutside(start);
    }

    // find solution
    while(!pq.empty()) {
        int p = *(--pq.end());
        int x = R[p];
        int y = C[p];
        pq.erase(p);
        build.erase({x,y});

        // update dsu
        RE(d,4) {
            int nx=x+dx4[d];
            int ny=y+dy4[d];
            if(build.count({nx,ny})) continue;
            if(!posID.count({nx,ny})) continue;
            unionSet(posID[{x,y}], posID[{nx,ny}]);
        }

        addOutside({R[p],C[p]});
        ans.pb(p);
    }

    if(ans.sz == n) {
        OUTL("YES");
        reverse(all(ans));
        FOR(i,ans) OUTL(i);
    } else {
        OUTL("NO");
    }
}

컴파일 시 표준 에러 (stderr) 메시지

skyscrapers.cpp: In function 'void program()':
skyscrapers.cpp:270:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(ans.sz == n) {
        ~~~~~~~^~~~

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 12 / 12
• Subtask 4: 17 / 17
• Subtask 5: 0 / 20
• Subtask 6: 10 / 10
• Subtask 7: 0 / 19