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답안 #559843

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
559843 2022-05-10T17:48:00 Z fatemetmhr Mousetrap (CEOI17_mousetrap) C++17
100 / 100
 648 ms 157028 KB 
// Be name khoda //
 
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
 
#define all(x)   x.begin(), x.end()
#define fi       first
#define se       second
#define pb       push_back
 
const int maxn5 = 1e6 + 10;
const int maxnt = 5e6 + 10;
const int inf   = 1e9;
 
int tale, mo, dp[maxn5], id[maxn5], newid = 0;
int htotale[maxn5], st[maxn5], parr[maxn5];
int valu[maxn5], valval[maxn5], zz[maxn5];
int cmp[maxn5];
vector <int> adj[maxn5], ver;
vector <pair<int, int>> av;
pair <int, int> mx[maxnt];
int mn[maxnt], lazy[maxnt], lazy2[maxnt];
 
inline bool dfs(int v, int par){
    if(v == tale){
        dp[v] = 0;
        htotale[v] = 0;
        return true;
    }
    int mx = 0, smx = 0;
    int z = -1;
    for(auto u : adj[v]) if(u != par){
        bool re = dfs(u, v);
        if(re){
            z = u;
        }
        if(dp[u] >= mx){
            smx = mx;
            mx = dp[u];
        }
        else
            smx = max(smx, dp[u]);
    }
    if(z == -1){
        dp[v] = smx + int(adj[v].size()) - 1;
        //cout << "false " << v << ' ' << dp[v] << endl;
        return false;
    }
 
    htotale[v] = htotale[z] + int(adj[v].size()) - 2 + (v == mo);
    ver.pb(v);
    parr[v] = par;
    zz[v] = z;
 
    //ft[ver.size()] = newid;
 
    return true;
}
 
 
inline bool ok(int v){
    for(int i = v; i <= ver.size(); i++){
        valval[i]--;
        if(valval[i] < 0)
            return false;
    }
    return true;
}
 
int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
 
    int n, a, b; cin >> n >> a >> b;
    a--; b--;
    mo = b;
    tale = a;
    for(int i = 0; i < n - 1; i++){
        int a, b; cin >> a >> b;
        a--; b--;
        adj[a].pb(b);
        adj[b].pb(a);
    }
 
    //assert(a != b);
 
    if(a == b)
        return cout << 0 << endl, 0;
 
    dfs(mo, -1);
 
    reverse(all(ver)); // az m be t hast
    //assert(ver.size() == 1);
 
    int mxx = 0, smx = 0;
    int pos = 1;
    for(auto v : ver){
        for(auto u : adj[v]) if(u != parr[v] && u != zz[v]){
            cmp[newid] = pos;
            valu[newid++] = dp[u] + htotale[v];
            //cout << v << ' ' << u << ' ' << dp[u] << ' ' << htotale[v] << endl;
            if(mxx <= dp[u] + htotale[v]){
                smx = mxx;
                mxx = dp[u] + htotale[v];
            }
            else
                smx = max(smx, dp[u] + htotale[v]);
            //cout << "aha " << v << ' ' << u << ' ' << dp[u] << ' ' << htotale[v] << endl;
        }
        st[pos] = newid;
        pos++;
    }
 
    //return cout << min(inf, smx) << endl, 0;
 
    
    //build(0, newid, 1);
    for(int i = 1; i <= ver.size(); i++)
        valval[i] = i;
    //build2(0, ver.size() + 1, 1);
 
    int done = 0;
    int ans = inf;
    //assert(st[pos - 1] == newid);
    //cout << newid << endl;
    if(newid == 0){
        return cout << 0 << endl, 0;
    }
    while(done < newid){
        int z = -1;
        for(int i = 0; i < newid; i++) if(z == -1 || valu[i] >= valu[z])
            z = i;
        //assert(done <= 1);
        ans = min(ans, valu[z] + done);
        //if(done == 1)
            //assert(mx[1].fi + done == smx);
        //if(done == 0)
            //assert(mx[1].fi == mxx);
        if(ok(cmp[z])){
            done++;
            for(int i = 0; i < st[cmp[z]]; i++)
                valu[i]--;
            valu[z] = -inf;
        }
        else
            break;
    }
    if(done == newid)
        ans = min(ans, done);
    //assert(done == 1);
    cout << ans << endl;
}

/*
Ino goosh kon bache jan ... in code e n^2 e vali kheili badihye ke mishe add o min max gereftano ba segment zad
pas nlog esh am badihye
*/

Compilation message

mousetrap.cpp: In function 'bool ok(int)':
mousetrap.cpp:65:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |     for(int i = v; i <= ver.size(); i++){
      |                    ~~^~~~~~~~~~~~~
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:120:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |     for(int i = 1; i <= ver.size(); i++)
      |                    ~~^~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23764 KB Output is correct
3 Correct 12 ms 23764 KB Output is correct
4 Correct 12 ms 23836 KB Output is correct
5 Correct 12 ms 23764 KB Output is correct
6 Correct 12 ms 23828 KB Output is correct
7 Correct 14 ms 23764 KB Output is correct
8 Correct 13 ms 23864 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 14 ms 23756 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 266 ms 58956 KB Output is correct
2 Correct 235 ms 55500 KB Output is correct
3 Correct 648 ms 60132 KB Output is correct
4 Correct 318 ms 42008 KB Output is correct
5 Correct 619 ms 60236 KB Output is correct
6 Correct 612 ms 60156 KB Output is correct

Subtask #3
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23764 KB Output is correct
3 Correct 12 ms 23764 KB Output is correct
4 Correct 12 ms 23836 KB Output is correct
5 Correct 12 ms 23764 KB Output is correct
6 Correct 12 ms 23828 KB Output is correct
7 Correct 14 ms 23764 KB Output is correct
8 Correct 13 ms 23864 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 14 ms 23756 KB Output is correct
11 Correct 12 ms 23764 KB Output is correct
12 Correct 15 ms 23892 KB Output is correct
13 Correct 13 ms 23884 KB Output is correct
14 Correct 12 ms 24020 KB Output is correct
15 Correct 14 ms 23932 KB Output is correct
16 Correct 15 ms 23892 KB Output is correct
17 Correct 12 ms 23824 KB Output is correct
18 Correct 13 ms 23892 KB Output is correct
19 Correct 12 ms 23876 KB Output is correct
20 Correct 15 ms 23924 KB Output is correct
21 Correct 12 ms 23892 KB Output is correct
22 Correct 12 ms 23892 KB Output is correct

Subtask #4
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23764 KB Output is correct
3 Correct 12 ms 23764 KB Output is correct
4 Correct 12 ms 23836 KB Output is correct
5 Correct 12 ms 23764 KB Output is correct
6 Correct 12 ms 23828 KB Output is correct
7 Correct 14 ms 23764 KB Output is correct
8 Correct 13 ms 23864 KB Output is correct
9 Correct 12 ms 23764 KB Output is correct
10 Correct 14 ms 23756 KB Output is correct
11 Correct 266 ms 58956 KB Output is correct
12 Correct 235 ms 55500 KB Output is correct
13 Correct 648 ms 60132 KB Output is correct
14 Correct 318 ms 42008 KB Output is correct
15 Correct 619 ms 60236 KB Output is correct
16 Correct 612 ms 60156 KB Output is correct
17 Correct 12 ms 23764 KB Output is correct
18 Correct 15 ms 23892 KB Output is correct
19 Correct 13 ms 23884 KB Output is correct
20 Correct 12 ms 24020 KB Output is correct
21 Correct 14 ms 23932 KB Output is correct
22 Correct 15 ms 23892 KB Output is correct
23 Correct 12 ms 23824 KB Output is correct
24 Correct 13 ms 23892 KB Output is correct
25 Correct 12 ms 23876 KB Output is correct
26 Correct 15 ms 23924 KB Output is correct
27 Correct 12 ms 23892 KB Output is correct
28 Correct 12 ms 23892 KB Output is correct
29 Correct 12 ms 23764 KB Output is correct
30 Correct 262 ms 59080 KB Output is correct
31 Correct 278 ms 59204 KB Output is correct
32 Correct 316 ms 157028 KB Output is correct
33 Correct 299 ms 137280 KB Output is correct
34 Correct 607 ms 60240 KB Output is correct
35 Correct 627 ms 60248 KB Output is correct
36 Correct 623 ms 71804 KB Output is correct
37 Correct 623 ms 72004 KB Output is correct
38 Correct 461 ms 73536 KB Output is correct
39 Correct 536 ms 73564 KB Output is correct
40 Correct 461 ms 73468 KB Output is correct