제출 #521232

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
521232		l3gendofyen	Building Skyscrapers (CEOI19_skyscrapers)	C++14	0 / 100	250 ms	14676 KiB

skyscrapers

#include<cstdio>
#include<algorithm>
#include<map>
#include<utility>
#include<vector>

using namespace std;

typedef pair<int, int> ii;
typedef vector<int> vi;

vi pset; vi prank;
void swap(int &a, int &b) {
    int tmp = a;
    a = b;
    b = tmp;
}
void initSet(int N) { pset.assign(N, 0); for(int i = 0; i< N; i++) pset[i] = i; prank.assign(N, 0);}
int findSet(int i) { return (pset[i] == i) ? i : (pset[i] = findSet(pset[i]));}
bool isSameSet(int i, int j) { return findSet(i) == findSet(j);}
void unionSet(int a, int b) {
    a = findSet(a);
    b = findSet(b);
    if (a != b) {
        if (prank[a] < prank[b])
            swap(a, b);
        pset[b] = a;
        if (prank[a] == prank[b])
            prank[a]++;
    }
}

map<ii, int> lookup;
int N, T;
ii scrapers[150010];

vector<ii> edges; // first item is always smaller

int dr[] = {0, 0, 1, 1, 1, -1, -1, -1};
int dc[] = {1, -1, 0, 1, -1, 0, 1, -1};

vi adj[150010];

bool vis[150010] = {};

void dfs(int u) {
    vis[u] = true;
    printf("%d\n", u + 1);
    for(auto v: adj[u]) {
        if(!vis[v]) {
            dfs(v);
        }
    }
}


int main(){
    scanf("%d%d", &N, &T);
    for(int i=0;i<N;i++){
        int r,c;
        scanf("%d%d", &r, &c);
        scrapers[i] = ii(r,c);
        lookup[ii(r, c)] = i;
    }

    for(int i=0;i<N;i++){
        ii cur = scrapers[i];
        int r = cur.first;
        int c = cur.second;
        for(int j=0;j<8;j++) {
            int nr = r + dr[j];
            int nc = c + dc[j];
           // printf("r c %d %d\n", r,c);
            //printf("nr nc %d %d\n", nr, nc);
            ii n = ii(nr, nc);
            if(lookup.count(n) != 0 && lookup[n] > i) {
                edges.push_back(ii(i, lookup[n]));
                //adj[i].push_back(lookup[ii]);
                //adj[lookup[ii]].push_back(i);
                //printf("%d %d\n", i, lookup[n]);
            }
        }
    }

    sort(edges.begin(), edges.end());
    reverse(edges.begin(), edges.end());
    initSet(N);

    int chosen = 0;
    while(chosen < N - 1) {
        if(edges.empty()) {
            printf("NO\n");
            return 0;
        }
        ii e = edges.back();edges.pop_back();
        int a = e.first; int b = e.second;
        if(!isSameSet(a, b)) {
            chosen++;
            adj[a].push_back(b);
            adj[b].push_back(a);
            unionSet(a, b);
        }
    }
    for(int i = 0;i< N;i++) {
        sort(adj[i].begin(), adj[i].end());
    }
    printf("YES\n");
    dfs(0);
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

skyscrapers.cpp: In function 'int main()':
skyscrapers.cpp:58:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |     scanf("%d%d", &N, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~
skyscrapers.cpp:61:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         scanf("%d%d", &r, &c);
      |         ~~~~~^~~~~~~~~~~~~~~~

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