Submission #287463

#	Time	Username	Problem	Language	Result	Execution time	Memory
287463		Namnamseo	철도 요금 (JOI16_ho_t3)	C++17	100 / 100	469 ms	50508 KiB

2016_ho_t3

#include <cstdio>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
typedef pair<int,int> pp;
priority_queue<pp> pq;

int n,m,q;

struct ES{
    int f,t;
    bool dead;
} ee[300010];

vector<int> edge    [300010];
vector<int> parent  [300010];
vector<int> child   [300010];
vector<int> child_ei[300010];

int  dijk[300010];
bool dead[300010];
int boolman;
int alive_pars[300010];

void dodijk(){
    int i;
    for(i=2;i<=n;++i) dijk[i]=1e9;
    pq.push(pp(0,1));
    int me;
    while(pq.size()){
        pp cur=pq.top(); pq.pop();
        if(dijk[me=cur.second]!=-cur.first) continue;
        int sz=edge[me].size(), nxt;
        for(i=0;i<sz;++i){
            ES& tmp=ee[edge[me][i]];
            nxt=tmp.f+tmp.t-me;
            
            if(dijk[nxt] > dijk[me]+1){
                dijk[nxt]=dijk[me]+1;
                pq.push(pp(-dijk[nxt],nxt));
                {
                    vector<int>().swap(parent[nxt]); // make empty
                    parent[nxt].clear();
                }
                parent[nxt].push_back(me);
                ++alive_pars[nxt];
                
                child [me].push_back(nxt);
                child_ei[me].push_back(edge[me][i]);
            } else if(dijk[nxt]==dijk[me]+1){
                parent[nxt].push_back(me);
                ++alive_pars[nxt];
                
                child [me].push_back(nxt);
                child_ei[me].push_back(edge[me][i]);
            }
        }
    }
}

void work(int x){
    if(alive_pars[x]==0 && !dead[x]){
        ++boolman;
        dead[x]=true;
        int i,sz=child[x].size(),nxt;
        for(i=0;i<sz;++i){
            nxt=child[x][i];
            if(!ee[child_ei[x][i]].dead){
                --alive_pars[nxt];
                work(nxt);
            }
        }
    }
}

int main()
{
    scanf("%d%d%d",&n,&m,&q);
    int i;
    for(i=1;i<=m;++i){
        int a,b;
        scanf("%d%d",&a,&b);
        ee[i].f=a; ee[i].t=b;
        ee[i].dead=false;
        edge[a].push_back(i);
        edge[b].push_back(i);
    }
    dodijk();
    
    for(;q--;){
        scanf("%d",&i);
        ee[i].dead=true;
        int a=ee[i].f, b=ee[i].t;
        if(dijk[a]>dijk[b]) swap(a,b);
        if(dijk[a]+1 == dijk[b]){
            if(!dead[a]){
                --alive_pars[b];
            }
            work(b);
        }
        printf("%d\n",boolman);
    }
    return 0;
}

Compilation message (stderr)

2016_ho_t3.cpp: In function 'int main()':
2016_ho_t3.cpp:79:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   79 |     scanf("%d%d%d",&n,&m,&q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
2016_ho_t3.cpp:83:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   83 |         scanf("%d%d",&a,&b);
      |         ~~~~~^~~~~~~~~~~~~~
2016_ho_t3.cpp:92:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   92 |         scanf("%d",&i);
      |         ~~~~~^~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 14 / 14
• Subtask 3: 35 / 35
• Subtask 4: 39 / 39