oj.uz

답안 #266870

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
266870 2020-08-15T13:48:48 Z MarcoMeijer Mousetrap (CEOI17_mousetrap) C++14
100 / 100
 1133 ms 213368 KB 
#include <bits/stdc++.h>
using namespace std;

// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e9
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }

// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }

//===================//
//  Added libraries  //
//===================//

//===================//
//end added libraries//
//===================//

void program();
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    program();
}


//===================//
//   begin program   //
//===================//

const int MX = 1e6+10;

int n, t, m;
int a[MX], b[MX];
int sm[MX];
vi adj[MX];
vi path;

bool dfsPath(int u, int p=-1) {
    if(u == t) {
        path.pb(u);
        return 1;
    }
    FOR(v,adj[u]) if(v != p) {
        if(dfsPath(v,u)) {
            path.pb(u);
            return 1;
        }
    }
    return 0;
}

int dp[MX];
vi res[MX];
void dfsDP(int u, int p=-1) {
    FOR(v,adj[u]) if(v != p) dfsDP(v,u);

    FOR(v,adj[u]) if(v != p) {
        res[u].pb(dp[v]);
    }
    sort(all(res[u]), greater<int>());
    if(res[u].sz <= 1) dp[u] = res[u].sz;
    else dp[u] = res[u][1]+res[u].sz;
}
void createDP(int u, int p=-1, int op=-1) {
    FOR(v,adj[u]) if(v != p && v != op) {
        dfsDP(v,u);
        res[u].pb(dp[v]);
    }
    sort(all(res[u]), greater<int>());
}

bool possible(int ub) {
    int canRem=1, rem=0;
    RE(i,path.sz-1) {
        int mx = ub - sm[i] - rem;
        int u = path[i];
        RE(j,res[u].sz) {
            if(res[u][j] > mx) {
                rem++;
                canRem--;
            }
        }
        if(canRem < 0) return 0;
        canRem++;
    }
    if(ub-rem < 0) return 0;
    return 1;
}

void program() {
    IN(n,t,m);
    RE(i,n-1) IN(a[i], b[i]);
    RE(i,n) adj[a[i]].pb(b[i]);
    RE(i,n) adj[b[i]].pb(a[i]);

    if(t == m) {
        OUTL(0);
        return;
    }

    dfsPath(m);
    reverse(all(path));


    sm[path.sz-1] = 0;
    RE(i,path.sz-1) {
        if(i == 0) createDP(path[i],path[i+1]);
        else createDP(path[i],path[i+1],path[i-1]);
    }
    REV(i,0,path.sz-1) {
        sm[i] = sm[i+1] + res[path[i]].sz;
    }

    possible(2);

    int lb=0, ub=INF;
    while(lb != ub) {
        int mid=(lb+ub)/2;
        if(possible(mid)) ub=mid;
        else lb=mid+1;
    }

    if(sm[0] == 0) lb = 0;

    OUTL(lb);
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 47352 KB Output is correct
2 Correct 31 ms 47352 KB Output is correct
3 Correct 30 ms 47360 KB Output is correct
4 Correct 30 ms 47360 KB Output is correct
5 Correct 30 ms 47352 KB Output is correct
6 Correct 32 ms 47360 KB Output is correct
7 Correct 29 ms 47360 KB Output is correct
8 Correct 30 ms 47360 KB Output is correct
9 Correct 32 ms 47360 KB Output is correct
10 Correct 30 ms 47360 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 407 ms 106104 KB Output is correct
2 Correct 368 ms 100092 KB Output is correct
3 Correct 875 ms 107936 KB Output is correct
4 Correct 416 ms 77580 KB Output is correct
5 Correct 866 ms 107768 KB Output is correct
6 Correct 875 ms 107924 KB Output is correct

Subtask #3
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 47352 KB Output is correct
2 Correct 31 ms 47352 KB Output is correct
3 Correct 30 ms 47360 KB Output is correct
4 Correct 30 ms 47360 KB Output is correct
5 Correct 30 ms 47352 KB Output is correct
6 Correct 32 ms 47360 KB Output is correct
7 Correct 29 ms 47360 KB Output is correct
8 Correct 30 ms 47360 KB Output is correct
9 Correct 32 ms 47360 KB Output is correct
10 Correct 30 ms 47360 KB Output is correct
11 Correct 28 ms 47360 KB Output is correct
12 Correct 30 ms 47488 KB Output is correct
13 Correct 29 ms 47360 KB Output is correct
14 Correct 30 ms 47488 KB Output is correct
15 Correct 29 ms 47360 KB Output is correct
16 Correct 30 ms 47360 KB Output is correct
17 Correct 29 ms 47360 KB Output is correct
18 Correct 31 ms 47352 KB Output is correct
19 Correct 29 ms 47360 KB Output is correct
20 Correct 30 ms 47360 KB Output is correct
21 Correct 30 ms 47360 KB Output is correct
22 Correct 30 ms 47352 KB Output is correct

Subtask #4
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 47352 KB Output is correct
2 Correct 31 ms 47352 KB Output is correct
3 Correct 30 ms 47360 KB Output is correct
4 Correct 30 ms 47360 KB Output is correct
5 Correct 30 ms 47352 KB Output is correct
6 Correct 32 ms 47360 KB Output is correct
7 Correct 29 ms 47360 KB Output is correct
8 Correct 30 ms 47360 KB Output is correct
9 Correct 32 ms 47360 KB Output is correct
10 Correct 30 ms 47360 KB Output is correct
11 Correct 407 ms 106104 KB Output is correct
12 Correct 368 ms 100092 KB Output is correct
13 Correct 875 ms 107936 KB Output is correct
14 Correct 416 ms 77580 KB Output is correct
15 Correct 866 ms 107768 KB Output is correct
16 Correct 875 ms 107924 KB Output is correct
17 Correct 28 ms 47360 KB Output is correct
18 Correct 30 ms 47488 KB Output is correct
19 Correct 29 ms 47360 KB Output is correct
20 Correct 30 ms 47488 KB Output is correct
21 Correct 29 ms 47360 KB Output is correct
22 Correct 30 ms 47360 KB Output is correct
23 Correct 29 ms 47360 KB Output is correct
24 Correct 31 ms 47352 KB Output is correct
25 Correct 29 ms 47360 KB Output is correct
26 Correct 30 ms 47360 KB Output is correct
27 Correct 30 ms 47360 KB Output is correct
28 Correct 30 ms 47352 KB Output is correct
29 Correct 28 ms 47352 KB Output is correct
30 Correct 413 ms 119700 KB Output is correct
31 Correct 426 ms 119416 KB Output is correct
32 Correct 459 ms 154972 KB Output is correct
33 Correct 485 ms 213368 KB Output is correct
34 Correct 933 ms 121012 KB Output is correct
35 Correct 893 ms 121208 KB Output is correct
36 Correct 1103 ms 125680 KB Output is correct
37 Correct 1133 ms 125780 KB Output is correct
38 Correct 763 ms 120528 KB Output is correct
39 Correct 752 ms 120504 KB Output is correct
40 Correct 749 ms 120664 KB Output is correct