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Submission #161079

# Submission time Handle Problem Language Result Execution time Memory
161079 2019-10-31T13:25:21 Z Akashi Mousetrap (CEOI17_mousetrap) C++14
100 / 100
 1132 ms 158688 KB 
#include <bits/stdc++.h>
using namespace std;

const int lim = 1e6 + 5;

int n, t, m;
int w[lim], h[lim], TT[lim];
vector <int> v[lim];

void dfs(int nod = t, int papa = 0){
    bool frunza = true;
    int Max = 0, Max2 = 0;

    for(auto it : v[nod]){
        if(papa == it) continue ;

        frunza = false;

        TT[it] = nod;
        w[it] = w[nod];
        h[it] = h[nod] + 1;
        if(nod != t) w[it] = w[it] + (v[nod].size() - 2);

        dfs(it, nod);

        if(w[it] > Max) Max2 = Max, Max = w[it];
        else if(w[it] > Max2) Max2 = w[it];
    }

    if(frunza) w[nod] = w[nod] + h[nod];
    else{
        if(Max2 == 0) w[nod] = w[nod] + h[nod] + 1;
        else w[nod] = Max2;
    }

}

inline bool check(int tmp){
    int cnt = 0;
    for(int nod = m, nr = 0, Last = 0; nod != t ; Last = nod, nod = TT[nod], ++nr){
        int aux = 0;
        for(auto it : v[nod]){
            if(it == TT[nod] || it == Last) continue ;

            if(w[it] - h[nod] - (nod != m) + cnt > tmp) ++aux;
        }

        cnt = cnt + aux;
        if(cnt > nr + 1) return 0;
    }

    if(cnt > tmp) return 0;

    return 1;
}

int main()
{
//    freopen("1.in", "r", stdin);

    scanf("%d%d%d", &n, &t, &m);

    int x, y;
    for(int i = 2; i <= n ; ++i){
        scanf("%d%d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }

    dfs();

    int st = 0, dr = 2 * n;
    while(st <= dr){
        int mij = (st + dr) / 2;

        if(check(mij)) dr = mij - 1;
        else st = mij + 1;
    }

    printf("%d", st);

    return 0;
}

Compilation message

mousetrap.cpp: In function 'int main()':
mousetrap.cpp:61:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &n, &t, &m);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:65:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &x, &y);
         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23800 KB Output is correct
2 Correct 24 ms 23864 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 25 ms 23860 KB Output is correct
5 Correct 24 ms 23800 KB Output is correct
6 Correct 24 ms 23928 KB Output is correct
7 Correct 27 ms 23800 KB Output is correct
8 Correct 26 ms 23800 KB Output is correct
9 Correct 24 ms 23800 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 453 ms 66908 KB Output is correct
2 Correct 409 ms 62584 KB Output is correct
3 Correct 1051 ms 68068 KB Output is correct
4 Correct 496 ms 46072 KB Output is correct
5 Correct 1074 ms 68156 KB Output is correct
6 Correct 1020 ms 68156 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23800 KB Output is correct
2 Correct 24 ms 23864 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 25 ms 23860 KB Output is correct
5 Correct 24 ms 23800 KB Output is correct
6 Correct 24 ms 23928 KB Output is correct
7 Correct 27 ms 23800 KB Output is correct
8 Correct 26 ms 23800 KB Output is correct
9 Correct 24 ms 23800 KB Output is correct
10 Correct 23 ms 23800 KB Output is correct
11 Correct 24 ms 23800 KB Output is correct
12 Correct 24 ms 23928 KB Output is correct
13 Correct 24 ms 23928 KB Output is correct
14 Correct 24 ms 23928 KB Output is correct
15 Correct 25 ms 23928 KB Output is correct
16 Correct 24 ms 23860 KB Output is correct
17 Correct 25 ms 23928 KB Output is correct
18 Correct 25 ms 23928 KB Output is correct
19 Correct 24 ms 23928 KB Output is correct
20 Correct 24 ms 23928 KB Output is correct
21 Correct 27 ms 23928 KB Output is correct
22 Correct 24 ms 23928 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23800 KB Output is correct
2 Correct 24 ms 23864 KB Output is correct
3 Correct 24 ms 23800 KB Output is correct
4 Correct 25 ms 23860 KB Output is correct
5 Correct 24 ms 23800 KB Output is correct
6 Correct 24 ms 23928 KB Output is correct
7 Correct 27 ms 23800 KB Output is correct
8 Correct 26 ms 23800 KB Output is correct
9 Correct 24 ms 23800 KB Output is correct
10 Correct 23 ms 23800 KB Output is correct
11 Correct 453 ms 66908 KB Output is correct
12 Correct 409 ms 62584 KB Output is correct
13 Correct 1051 ms 68068 KB Output is correct
14 Correct 496 ms 46072 KB Output is correct
15 Correct 1074 ms 68156 KB Output is correct
16 Correct 1020 ms 68156 KB Output is correct
17 Correct 24 ms 23800 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 24 ms 23928 KB Output is correct
20 Correct 24 ms 23928 KB Output is correct
21 Correct 25 ms 23928 KB Output is correct
22 Correct 24 ms 23860 KB Output is correct
23 Correct 25 ms 23928 KB Output is correct
24 Correct 25 ms 23928 KB Output is correct
25 Correct 24 ms 23928 KB Output is correct
26 Correct 24 ms 23928 KB Output is correct
27 Correct 27 ms 23928 KB Output is correct
28 Correct 24 ms 23928 KB Output is correct
29 Correct 24 ms 23928 KB Output is correct
30 Correct 472 ms 80504 KB Output is correct
31 Correct 466 ms 80284 KB Output is correct
32 Correct 683 ms 158648 KB Output is correct
33 Correct 515 ms 158688 KB Output is correct
34 Correct 1104 ms 81480 KB Output is correct
35 Correct 1081 ms 81396 KB Output is correct
36 Correct 1035 ms 89180 KB Output is correct
37 Correct 1132 ms 88912 KB Output is correct
38 Correct 842 ms 91896 KB Output is correct
39 Correct 1028 ms 91896 KB Output is correct
40 Correct 845 ms 91924 KB Output is correct