Submission #184109

#	Time	Username	Problem	Language	Result	Execution time	Memory
184109		rzbt	Evacuation plan (IZhO18_plan)	C++14	100 / 100	1515 ms	65700 KiB

plan

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define MAXN 100005
typedef long long ll;

using namespace std;

int n,m;
vector<pair<int,pair<int,int> > > grane;
vector<pair<int,int> > stablo[MAXN],niz[MAXN];
int pre[MAXN][20];
int cale[MAXN],masa[MAXN],dub[MAXN];
int docal[MAXN],udalj[MAXN];

int koren(int p){
    while(p!=cale[p])p=cale[p];
    return p;
}

void spoji(int a,int b,int masa2){

    a=koren(a);
    b=koren(b);

    if(a==b)return;

    if(masa[a]<masa[b])swap(a,b);
    //printf("   %d %d     %d\n",a,b,masa2);
    pre[b][0]=a;
    docal[b]=masa2;
    stablo[a].pb(mp(b,masa2));
    masa[a]+=masa[b];
    cale[b]=a;
}

void dfsS(int t,int o,int h){
   // printf("   %d %d\n",t,h);
    dub[t]=h;
    for(auto x:stablo[t])
        dfsS(x.F,t,h+1);

}
int resi(int a,int b){
    //printf("     %d %d   ",dub[a],dub[b]);
    if(dub[b]>dub[a])swap(a,b);
    for(int j=19;j>=0;j--)
        if(pre[a][j]!=0 && dub[pre[a][j]]>dub[b])a=pre[a][j];

    if(a==b)return udalj[a];
    if(pre[a][0]==b)return docal[a];
    //printf("NISAM GOTOV   ");
    if(dub[a]!=dub[b])a=pre[a][0];
    for(int j=19;j>=0;j--)
        if(pre[a][j]!=pre[b][j])a=pre[a][j],b=pre[b][j];
    //printf("    %d %d  ", a,b);
    return min(docal[a],docal[b]);

}

set<pair<int,int> > q;
bool obidjen[MAXN];
void dijkstra(){
    while(!q.empty()){
        pair<int,int> t=*q.begin();
        q.erase(q.begin());
        if(obidjen[t.S])continue;
        obidjen[t.S]=true;
        udalj[t.S]=t.F;
        for(auto x:niz[t.S]){
            if(obidjen[x.F])continue;
            q.insert(mp(x.S+t.F,x.F));
        }

    }
}


int main()
{
    scanf("%d %d", &n, &m);
    for(int i=1;i<=n;i++){
        cale[i]=i;
        masa[i]=1;
    }
    for(int i=1;i<=m;i++){
        int t1,t2,t3;
        scanf("%d %d %d", &t1, &t2, &t3);
        niz[t1].pb(mp(t2,t3));
        niz[t2].pb(mp(t1,t3));

        grane.pb(mp(t3,mp(t1,t2)));
    }

    int k;
    scanf("%d", &k);
    while(k--){
        int t;
        scanf("%d", &t);
        q.insert(mp(0,t));
        //printf("gotov");
    }
    dijkstra();
    for(auto it=grane.begin();it!=grane.end();it++)it->F=-min(udalj[it->S.F],udalj[it->S.S]);
    sort(all(grane));
    for(auto x:grane)
        spoji(x.S.F,x.S.S,min(udalj[x.S.F],udalj[x.S.S]));
    for(int j=1;j<20;j++){
        for(int i=1;i<=n;i++)
            pre[i][j]=pre[pre[i][j-1]][j-1];
    }
    dfsS(koren(1),0,1);
    int qq;
    scanf("%d", &qq);
    while(qq--){
        int a,b;
        scanf("%d %d", &a, &b);
        printf("%d\n",resi(a,b));

    }
    return 0;
}

Compilation message (stderr)

plan.cpp: In function 'int main()':
plan.cpp:84:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
plan.cpp:91:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d %d", &t1, &t2, &t3);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp:99:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &k);
     ~~~~~^~~~~~~~~~
plan.cpp:102:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &t);
         ~~~~~^~~~~~~~~~
plan.cpp:117:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &qq);
     ~~~~~^~~~~~~~~~~
plan.cpp:120:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &a, &b);
         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46