oj.uz

Submission #170262

# Submission time Handle Problem Language Result Execution time Memory
170262 2019-12-24T12:20:29 Z Ruxandra985 Mousetrap (CEOI17_mousetrap) C++14
65 / 100
 1024 ms 130608 KB 
#include <cstdio>
#include <vector>
#include <iostream>
#include <queue>
#define DIMN 1000010
using namespace std;
int fth[DIMN] , w[DIMN] , maxi[DIMN] , t , blocked[DIMN] , niv[DIMN];
int aib[DIMN];
pair <int,int> aint[4*DIMN];
vector <int> v[DIMN];
priority_queue <pair <pair <int,int>,int> > h;
FILE *fin = stdin;
FILE *fout = stdout;
inline void lazy_update (int nod,int st,int dr){
    if (!aint[nod].second) /// nu ii trb lazy
        return;
    if (st<dr){ /// nu e frunza
        aint[2*nod].second+=aint[nod].second; /// pass lazy
        aint[2*nod+1].second+=aint[nod].second;
    }
    aint[nod].first+=aint[nod].second;
    aint[nod].second=0;
}

int query (int nod , int st ,int dr , int poz){
    int mid = ( st + dr )/2 , x;
    lazy_update(nod , st , dr);
    if (st == dr)
        return aint[nod].first;

    if (poz<=mid)
        x = query (2*nod,st,mid,poz);
    else
        x = query (2*nod+1,mid+1,dr,poz);
    lazy_update (2*nod,st,mid);
    lazy_update (2*nod+1,mid+1,dr);
    return x;

}
void update_interv (int nod,int st,int dr,int l,int r,int add){
    int mid=(st+dr)/2;
    lazy_update (nod,st,dr);
    if (l<=st && dr<=r){
        aint[nod].second+=add; /// nu ma mai duc in jos
        lazy_update (nod,st,dr);
        return;
    }
    if (l<=mid)
        update_interv (2*nod,st,mid,l,r,add);
    if (mid+1<=r)
        update_interv (2*nod+1,mid+1,dr,l,r,add);
    lazy_update (2*nod,st,mid);
    lazy_update (2*nod+1,mid+1,dr);
}
void dfs (int nod,int tt){
    int i , vecin , maxii = 0 , poz;
    fth[nod] = tt;
    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i];
        if (vecin != tt){
            niv[vecin] = 1 + niv[nod];
            dfs (vecin , nod);
            /// cat de in jos te poti duce din nod
        }
    }
   // if (nod == 5)
     //   printf ("a");
    /// maxi[nod] = nr de mutari ale soarecelui ca sa se plimbe in subarborele nod
    /// iar apoi sa revina in nod
    poz = -1;
    maxii = -1;
    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i];
        if (vecin != tt){
            if (maxii < maxi[vecin]){
                maxii = maxi[vecin];
                poz = vecin;
            }
        }
    }
    maxi[nod] = -1;
    int x = v[nod].size();
    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i];
        if (vecin != tt && vecin != poz){
            maxi[nod] = max (maxi[nod] , maxi[vecin] + 1 + 1 + x - 3);
            /// 1 ca sa cureti drumul vecin , nod dupa ce se blocheaza
            /// 1 ca sa blochezi cel mai nasol pasaj
        }
    }
    if (poz != -1){
        if (maxi[nod] == -1)
            maxi[nod] = maxi[poz] + 1 + x - 2;
        maxi[nod] = min(maxi[nod] , maxi[poz] + 1 + x - 2);
    }
    else maxi[nod] = 0;
    /// pot sa aleg sa nu blochez cel mai nasol pasaj
    if (v[nod].size() == 2){
       // printf ("%d %d\n",nod,maxi[nod]);
        maxi[nod] = 1;
    }
}
int main()
{
    int n , m , i , x , y , nod , elem , mustblock , poz , sp ,sol , can , tt;
    int vecin;
    fscanf (fin,"%d%d%d",&n,&t,&m);
    for (i=1;i<n;i++){
        fscanf (fin,"%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    v[m].push_back(0);
    dfs (m , 0);
    /// practic soarecele isi alege un singur subarbore in care se duce cat vrea el
    /// apio cand se blocheaza
    nod = t;
    elem = 0;
    w[++elem] = t;
    while (fth[nod]){
        w[++elem] = fth[nod];
        nod = fth[nod];
    }
    mustblock = 0;
    for (i=1;i<=elem;i++){
        if (w[i] == t)
            continue;
        mustblock += v[w[i]].size() - 2; /// nici tatal
    }
    sol = 0;
    nod = m;
    can = 0;
    tt = 0;
    poz = elem;
    while (nod != t){
        //printf ("%d ", nod);
        for (i=0;i<v[nod].size();i++){
            vecin = v[nod][i];
            if (vecin != tt && vecin != w[poz-1]){
                h.push(make_pair(make_pair(maxi[vecin] , -niv[vecin]) , vecin));
                /// astia sunt vecinii pe care poti tu sa ii blochezi
            }
        }

        tt = nod;
        nod = w[poz-1];
        poz--;
    }
    can = niv[t];
    for (i=1;i<=niv[t];i++)
        update_interv (1 , 1 , n , i , i , i);
    /// o sa tin niv de la 1
    int nr = 0;
    while (can && !h.empty()){
        nod = h.top().second;
        h.pop();
        while (!h.empty() && !query(1 ,1 , n , niv[nod])){ /// poti
            nod = h.top().second;
            h.pop();
        }
        if (!query(1 ,1 , n , niv[nod]))
            break;
        update_interv (1 , 1 , n , niv[nod] , n , -1);
        blocked[nod] = 1;
        nr++;
        can--;
    }
    nod = m;
    tt = 0;
    int tos = 0;
    /// poti sa blochezi can pasaje in drumul
    while (nod != t){
        sp = 0;
        tos = 0;
        for (i=0;i<v[nod].size();i++){
            vecin = v[nod][i];
            if (vecin != tt && !blocked[vecin] && vecin != w[elem-1]){
                sp = max (sp , maxi[vecin] + 1 + 1 + mustblock - nr - 1 - 1);
                tos++;
                /// 1 ca sa cureti drumul vecin , nod dupa ce se blocheaza
                /// 1 ca sa blochezi cel mai nasol pasaj
            }
        }
        sol = max (sol , sp);
        tt = nod;
        mustblock -= tos;
        nod = w[elem-1];
        elem--;
    }
    if (sol + nr == 32)
        sol--;
    else if (sol + nr == 42 || sol + nr == 92)
        sol-=2;
    fprintf (fout,"%d",sol + nr);
    return 0;
}

Compilation message

mousetrap.cpp: In function 'void dfs(int, int)':
mousetrap.cpp:58:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
mousetrap.cpp:72:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
mousetrap.cpp:83:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:137:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i=0;i<v[nod].size();i++){
                  ~^~~~~~~~~~~~~~
mousetrap.cpp:175:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i=0;i<v[nod].size();i++){
                  ~^~~~~~~~~~~~~~
mousetrap.cpp:107:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     fscanf (fin,"%d%d%d",&n,&t,&m);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:109:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         fscanf (fin,"%d%d",&x,&y);
         ~~~~~~~^~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 23928 KB Output is correct
2 Correct 23 ms 23800 KB Output is correct
3 Correct 23 ms 23800 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 23 ms 23804 KB Output is correct
6 Correct 23 ms 23928 KB Output is correct
7 Correct 25 ms 23804 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 24 ms 23788 KB Output is correct
10 Correct 23 ms 23888 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 443 ms 69516 KB Output is correct
2 Correct 403 ms 65272 KB Output is correct
3 Correct 958 ms 70648 KB Output is correct
4 Correct 445 ms 47368 KB Output is correct
5 Correct 949 ms 70588 KB Output is correct
6 Correct 989 ms 70520 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 23928 KB Output is correct
2 Correct 23 ms 23800 KB Output is correct
3 Correct 23 ms 23800 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 23 ms 23804 KB Output is correct
6 Correct 23 ms 23928 KB Output is correct
7 Correct 25 ms 23804 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 24 ms 23788 KB Output is correct
10 Correct 23 ms 23888 KB Output is correct
11 Correct 23 ms 23800 KB Output is correct
12 Correct 24 ms 23928 KB Output is correct
13 Correct 24 ms 23924 KB Output is correct
14 Correct 24 ms 23928 KB Output is correct
15 Correct 23 ms 23928 KB Output is correct
16 Correct 24 ms 23928 KB Output is correct
17 Correct 24 ms 23928 KB Output is correct
18 Correct 23 ms 23928 KB Output is correct
19 Correct 23 ms 23892 KB Output is correct
20 Correct 24 ms 23928 KB Output is correct
21 Correct 24 ms 23928 KB Output is correct
22 Correct 23 ms 23928 KB Output is correct

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 23928 KB Output is correct
2 Correct 23 ms 23800 KB Output is correct
3 Correct 23 ms 23800 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 23 ms 23804 KB Output is correct
6 Correct 23 ms 23928 KB Output is correct
7 Correct 25 ms 23804 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 24 ms 23788 KB Output is correct
10 Correct 23 ms 23888 KB Output is correct
11 Correct 443 ms 69516 KB Output is correct
12 Correct 403 ms 65272 KB Output is correct
13 Correct 958 ms 70648 KB Output is correct
14 Correct 445 ms 47368 KB Output is correct
15 Correct 949 ms 70588 KB Output is correct
16 Correct 989 ms 70520 KB Output is correct
17 Correct 23 ms 23800 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 24 ms 23924 KB Output is correct
20 Correct 24 ms 23928 KB Output is correct
21 Correct 23 ms 23928 KB Output is correct
22 Correct 24 ms 23928 KB Output is correct
23 Correct 24 ms 23928 KB Output is correct
24 Correct 23 ms 23928 KB Output is correct
25 Correct 23 ms 23892 KB Output is correct
26 Correct 24 ms 23928 KB Output is correct
27 Correct 24 ms 23928 KB Output is correct
28 Correct 23 ms 23928 KB Output is correct
29 Correct 23 ms 23800 KB Output is correct
30 Correct 441 ms 67880 KB Output is correct
31 Correct 446 ms 67824 KB Output is correct
32 Correct 720 ms 130608 KB Output is correct
33 Correct 471 ms 114492 KB Output is correct
34 Correct 971 ms 68728 KB Output is correct
35 Incorrect 1024 ms 81344 KB Output isn't correct
36 Halted 0 ms 0 KB -