Submission #52338

# Submission time Handle Problem Language Result Execution time Memory
52338 2018-06-25T12:57:59 Z Alexa2001 007 (CEOI14_007) C++17
76.6667 / 100
334 ms 27044 KB
#include <bits/stdc++.h>

using namespace std;
/// 15:26

const int Nmax = 2e5 + 5, inf = 2e9;

int n, m, A, B, S, D, i, x, y;
int dist1[Nmax], dist2[Nmax];
vector<int> v[Nmax];

bool adv(int &node)
{
    for(auto it : v[node])
        if(dist1[it] == dist1[node] - 1 && dist2[it] == dist2[node] - 1)
        {
            node = it;
            return 1;
        }
    return 0;
}

bool win(int tmp)
{
    int a, b, c, d;
    a = dist1[D], b = dist2[D];
    c = dist1[S] + tmp, d = dist2[S] + tmp;

    if(a < c || b < d) return 0;
    if(c < a && c < b) return 1;
    if(d < a && d < b) return 1;
    if(a == c && b > d) return 1;
    if(b == d && a > c) return 1;

    /// pana aici totul e frumos, iese pe hartie
    /// si acum vine cazul naspa, cireasa de pe tort
    /// avem a = c si b = d
    /// trebuie sa vedem care dintre aia doi ajunge primul la un nod care nu mai are continuare echidistanta fata de A si B
    /// cred ca nu se intersecteaza pe parcurs, cred...

    assert(a==c && b==d); /// sa ma aigur ca totusi n-am scapat ceva

    int i, ss = S, dd = D;
    for(i=1; i<=a; ++i)
    {
        if(!adv(dd)) return 1;
        if(i<=tmp) continue;
        if(!adv(ss)) return 0;
    }
    assert(0);
}

int solve()
{
    int st = 0, dr = n, mid;
    while(st <= dr)
    {
        mid = (st+dr)/2;
        if(!win(mid)) dr = mid-1;
            else st = mid+1;
    }
    return dr;
}

void calc(int node, int d[])
{
    int i;
    for(i=1; i<=n; ++i) d[i] = inf;

    queue<int> q;
    d[node] = 0;
    q.push(node);

    while(q.size())
    {
        node = q.front();
        q.pop();
        for(auto it : v[node])
            if(d[it] == inf)
            {
                d[it] = d[node] + 1;
                q.push(it);
            }
    }
}

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

    cin >> n >> m;
    cin >> S >> D >> A >> B;

    for(i=1; i<=m; ++i)
    {
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    calc(A, dist1);
    calc(B, dist2);

    cout << solve() << '\n';

    return 0;
}
# Verdict Execution time Memory Grader output
1 Correct 7 ms 4984 KB Output is correct
2 Correct 6 ms 5092 KB Output is correct
3 Correct 7 ms 5168 KB Output is correct
4 Correct 6 ms 5168 KB Output is correct
5 Correct 7 ms 5344 KB Output is correct
6 Correct 6 ms 5344 KB Output is correct
7 Correct 6 ms 5344 KB Output is correct
8 Correct 6 ms 5344 KB Output is correct
9 Correct 6 ms 5344 KB Output is correct
10 Correct 7 ms 5344 KB Output is correct
11 Correct 6 ms 5344 KB Output is correct
12 Correct 7 ms 5356 KB Output is correct
13 Correct 7 ms 5356 KB Output is correct
14 Correct 6 ms 5356 KB Output is correct
15 Correct 7 ms 5356 KB Output is correct
16 Correct 7 ms 5356 KB Output is correct
17 Correct 7 ms 5484 KB Output is correct
18 Correct 8 ms 5484 KB Output is correct
19 Correct 8 ms 5484 KB Output is correct
20 Correct 7 ms 5484 KB Output is correct
21 Correct 6 ms 5484 KB Output is correct
22 Correct 6 ms 5484 KB Output is correct
23 Correct 7 ms 5484 KB Output is correct
24 Correct 7 ms 5484 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 29 ms 6908 KB Output is correct
2 Correct 48 ms 7548 KB Output is correct
3 Correct 40 ms 7548 KB Output is correct
4 Correct 46 ms 7676 KB Output is correct
5 Correct 43 ms 7676 KB Output is correct
6 Correct 52 ms 7676 KB Output is correct
7 Correct 31 ms 7676 KB Output is correct
8 Correct 39 ms 7676 KB Output is correct
9 Correct 48 ms 7676 KB Output is correct
10 Correct 193 ms 12108 KB Output is correct
11 Correct 62 ms 12108 KB Output is correct
12 Correct 85 ms 12108 KB Output is correct
13 Correct 71 ms 12108 KB Output is correct
14 Correct 71 ms 12108 KB Output is correct
15 Correct 110 ms 12108 KB Output is correct
16 Correct 110 ms 12108 KB Output is correct
17 Correct 75 ms 12108 KB Output is correct
18 Correct 105 ms 12108 KB Output is correct
19 Correct 131 ms 12108 KB Output is correct
20 Correct 239 ms 13564 KB Output is correct
21 Correct 129 ms 13564 KB Output is correct
22 Correct 105 ms 13564 KB Output is correct
23 Runtime error 185 ms 22652 KB Execution killed with signal 11 (could be triggered by violating memory limits)
24 Correct 116 ms 22652 KB Output is correct
25 Correct 134 ms 22652 KB Output is correct
26 Runtime error 101 ms 22652 KB Execution killed with signal 11 (could be triggered by violating memory limits)
27 Correct 119 ms 22652 KB Output is correct
28 Correct 127 ms 22652 KB Output is correct
29 Correct 166 ms 22652 KB Output is correct
30 Correct 250 ms 24844 KB Output is correct
31 Correct 143 ms 24844 KB Output is correct
32 Correct 141 ms 24844 KB Output is correct
33 Correct 137 ms 24844 KB Output is correct
34 Correct 174 ms 24844 KB Output is correct
35 Correct 131 ms 24844 KB Output is correct
36 Correct 139 ms 24844 KB Output is correct
37 Correct 151 ms 24844 KB Output is correct
38 Correct 163 ms 24844 KB Output is correct
39 Correct 170 ms 24844 KB Output is correct
40 Correct 250 ms 24952 KB Output is correct
41 Correct 334 ms 27044 KB Output is correct