oj.uz

Submission #170257

# Submission time Handle Problem Language Result Execution time Memory
170257 2019-12-24T12:05:45 Z Ruxandra985 Mousetrap (CEOI17_mousetrap) C++14
65 / 100
 1038 ms 143700 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;
/// nu sunt foarte mandra de ce am facut
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-=2;
    fprintf (fout,"%d",sol + nr);
    return 0;
}

Compilation message

mousetrap.cpp: In function 'void dfs(int, int)':
mousetrap.cpp:59:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
mousetrap.cpp:73:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
mousetrap.cpp:84:15: 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:138:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i=0;i<v[nod].size();i++){
                  ~^~~~~~~~~~~~~~
mousetrap.cpp:176:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i=0;i<v[nod].size();i++){
                  ~^~~~~~~~~~~~~~
mousetrap.cpp:108:12: 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:110:16: 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 22 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 24 ms 23928 KB Output is correct
6 Correct 24 ms 23928 KB Output is correct
7 Correct 23 ms 23800 KB Output is correct
8 Correct 27 ms 23928 KB Output is correct
9 Correct 23 ms 23928 KB Output is correct
10 Correct 23 ms 23800 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 442 ms 73976 KB Output is correct
2 Correct 397 ms 66936 KB Output is correct
3 Correct 973 ms 75296 KB Output is correct
4 Correct 464 ms 52528 KB Output is correct
5 Correct 1038 ms 74060 KB Output is correct
6 Correct 963 ms 73976 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 22 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 24 ms 23928 KB Output is correct
6 Correct 24 ms 23928 KB Output is correct
7 Correct 23 ms 23800 KB Output is correct
8 Correct 27 ms 23928 KB Output is correct
9 Correct 23 ms 23928 KB Output is correct
10 Correct 23 ms 23800 KB Output is correct
11 Correct 23 ms 23800 KB Output is correct
12 Correct 23 ms 23928 KB Output is correct
13 Correct 24 ms 23928 KB Output is correct
14 Correct 24 ms 24056 KB Output is correct
15 Correct 24 ms 23928 KB Output is correct
16 Correct 24 ms 23928 KB Output is correct
17 Correct 23 ms 23928 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 23 ms 23928 KB Output is correct
20 Correct 24 ms 23912 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 22 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 24 ms 23928 KB Output is correct
6 Correct 24 ms 23928 KB Output is correct
7 Correct 23 ms 23800 KB Output is correct
8 Correct 27 ms 23928 KB Output is correct
9 Correct 23 ms 23928 KB Output is correct
10 Correct 23 ms 23800 KB Output is correct
11 Correct 442 ms 73976 KB Output is correct
12 Correct 397 ms 66936 KB Output is correct
13 Correct 973 ms 75296 KB Output is correct
14 Correct 464 ms 52528 KB Output is correct
15 Correct 1038 ms 74060 KB Output is correct
16 Correct 963 ms 73976 KB Output is correct
17 Correct 23 ms 23800 KB Output is correct
18 Correct 23 ms 23928 KB Output is correct
19 Correct 24 ms 23928 KB Output is correct
20 Correct 24 ms 24056 KB Output is correct
21 Correct 24 ms 23928 KB Output is correct
22 Correct 24 ms 23928 KB Output is correct
23 Correct 23 ms 23928 KB Output is correct
24 Correct 24 ms 23928 KB Output is correct
25 Correct 23 ms 23928 KB Output is correct
26 Correct 24 ms 23912 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 23804 KB Output is correct
30 Correct 442 ms 80488 KB Output is correct
31 Correct 451 ms 80444 KB Output is correct
32 Correct 717 ms 143700 KB Output is correct
33 Correct 473 ms 127308 KB Output is correct
34 Incorrect 951 ms 81548 KB Output isn't correct
35 Halted 0 ms 0 KB -