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Submission #54228

# Submission time Handle Problem Language Result Execution time Memory
54228 2018-07-02T21:09:27 Z SpaimaCarpatilor Mousetrap (CEOI17_mousetrap) C++17
100 / 100
 1212 ms 250968 KB 
#include<bits/stdc++.h>

using namespace std;

int nr, N, mouse, trap, t[1000009], dp[1000009], sda[1000009], deg[1000009], node[1000009];
vector < int > v[1000009], h[1000009];

void dfs (int nod)
{
    sda[nod] = (nod == trap ? 0 : sda[t[nod]] - 1 + (int) (v[nod].size ()) - 1);
    for (auto it : v[nod])
        if (it != t[nod])
            t[it] = nod, dfs (it), deg[nod] ++;
    if (deg[nod] <= 1) dp[nod] = deg[nod];
    else
    {
        int max1 = -N, max2 = -N;
        for (auto it : v[nod])
            if (it != t[nod])
            {
                if (dp[it] > max1) max2 = max1, max1 = dp[it];
                else
                if (dp[it] > max2) max2 = dp[it];
            }
        dp[nod] = deg[nod] + max2;
    }
}

int getDp (int i, int cnt)
{
    if (cnt >= h[i].size ()) return 0;
    return h[i][cnt];
}

bool ok (int D)
{
    int minS = 0;
    for (int i=1; i<nr; i++)
    {
        int oldS = minS;
        while (minS <= i && max (0, sda[t[node[i]]] - (i - minS)) + getDp (i, minS - oldS) +
                            max (0, deg[node[i]] - (i > 1) - (minS - oldS)) + min (i, sda[t[node[i]]] + minS) > D)
            minS ++;
        if (minS > i) return 0;
    }
    return 1;
}

int main ()
{
//freopen ("input", "r", stdin);
//freopen ("output", "w", stdout);

scanf ("%d %d %d", &N, &trap, &mouse);
for (int i=1; i<N; i++)
{
    int x, y;
    scanf ("%d %d", &x, &y);
    v[x].push_back (y);
    v[y].push_back (x);
}
dfs (trap);
node[1] = mouse, nr = 1;
while (node[nr] != trap)
    node[nr + 1] = t[node[nr]], nr ++;
for (int i=1; i<=nr; i++)
{
    for (auto j : v[node[i]])
        if (j != t[node[i]] && j != node[i - 1])
            h[i].push_back (dp[j]);
    sort (h[i].begin (), h[i].end ());
    reverse (h[i].begin (), h[i].end ());
}
int p = 0, u = N, mij, ras = -1;
while (p <= u)
{
    mij = (p + u) >> 1;
    if (ok (mij)) ras = mij, u = mij - 1;
    else p = mij + 1;
}
printf ("%d\n", ras);
return 0;
}

Compilation message

mousetrap.cpp: In function 'int getDp(int, int)':
mousetrap.cpp:31:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (cnt >= h[i].size ()) return 0;
         ~~~~^~~~~~~~~~~~~~~
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:54:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf ("%d %d %d", &N, &trap, &mouse);
 ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:58:11: 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 39 ms 47352 KB Output is correct
2 Correct 41 ms 47396 KB Output is correct
3 Correct 40 ms 47580 KB Output is correct
4 Correct 39 ms 47580 KB Output is correct
5 Correct 41 ms 47604 KB Output is correct
6 Correct 40 ms 47604 KB Output is correct
7 Correct 42 ms 47628 KB Output is correct
8 Correct 41 ms 47632 KB Output is correct
9 Correct 41 ms 47632 KB Output is correct
10 Correct 40 ms 47708 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 495 ms 92756 KB Output is correct
2 Correct 425 ms 92756 KB Output is correct
3 Correct 1063 ms 95852 KB Output is correct
4 Correct 580 ms 95852 KB Output is correct
5 Correct 1018 ms 95852 KB Output is correct
6 Correct 1212 ms 95852 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 47352 KB Output is correct
2 Correct 41 ms 47396 KB Output is correct
3 Correct 40 ms 47580 KB Output is correct
4 Correct 39 ms 47580 KB Output is correct
5 Correct 41 ms 47604 KB Output is correct
6 Correct 40 ms 47604 KB Output is correct
7 Correct 42 ms 47628 KB Output is correct
8 Correct 41 ms 47632 KB Output is correct
9 Correct 41 ms 47632 KB Output is correct
10 Correct 40 ms 47708 KB Output is correct
11 Correct 40 ms 95852 KB Output is correct
12 Correct 41 ms 95852 KB Output is correct
13 Correct 42 ms 95852 KB Output is correct
14 Correct 42 ms 95852 KB Output is correct
15 Correct 42 ms 95852 KB Output is correct
16 Correct 40 ms 95852 KB Output is correct
17 Correct 41 ms 95852 KB Output is correct
18 Correct 41 ms 95852 KB Output is correct
19 Correct 40 ms 95852 KB Output is correct
20 Correct 40 ms 95852 KB Output is correct
21 Correct 40 ms 95852 KB Output is correct
22 Correct 40 ms 95852 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 47352 KB Output is correct
2 Correct 41 ms 47396 KB Output is correct
3 Correct 40 ms 47580 KB Output is correct
4 Correct 39 ms 47580 KB Output is correct
5 Correct 41 ms 47604 KB Output is correct
6 Correct 40 ms 47604 KB Output is correct
7 Correct 42 ms 47628 KB Output is correct
8 Correct 41 ms 47632 KB Output is correct
9 Correct 41 ms 47632 KB Output is correct
10 Correct 40 ms 47708 KB Output is correct
11 Correct 495 ms 92756 KB Output is correct
12 Correct 425 ms 92756 KB Output is correct
13 Correct 1063 ms 95852 KB Output is correct
14 Correct 580 ms 95852 KB Output is correct
15 Correct 1018 ms 95852 KB Output is correct
16 Correct 1212 ms 95852 KB Output is correct
17 Correct 40 ms 95852 KB Output is correct
18 Correct 41 ms 95852 KB Output is correct
19 Correct 42 ms 95852 KB Output is correct
20 Correct 42 ms 95852 KB Output is correct
21 Correct 42 ms 95852 KB Output is correct
22 Correct 40 ms 95852 KB Output is correct
23 Correct 41 ms 95852 KB Output is correct
24 Correct 41 ms 95852 KB Output is correct
25 Correct 40 ms 95852 KB Output is correct
26 Correct 40 ms 95852 KB Output is correct
27 Correct 40 ms 95852 KB Output is correct
28 Correct 40 ms 95852 KB Output is correct
29 Correct 40 ms 95852 KB Output is correct
30 Correct 468 ms 106336 KB Output is correct
31 Correct 485 ms 119616 KB Output is correct
32 Correct 642 ms 201680 KB Output is correct
33 Correct 493 ms 211124 KB Output is correct
34 Correct 1135 ms 211124 KB Output is correct
35 Correct 1088 ms 211124 KB Output is correct
36 Correct 1165 ms 211124 KB Output is correct
37 Correct 1118 ms 212236 KB Output is correct
38 Correct 1016 ms 224156 KB Output is correct
39 Correct 911 ms 237476 KB Output is correct
40 Correct 991 ms 250968 KB Output is correct