oj.uz

Submission #59750

# Submission time Handle Problem Language Result Execution time Memory
59750 2018-07-23T04:09:55 Z Benq Beads and wires (APIO14_beads) C++11
100 / 100
 394 ms 32032 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
 
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
 
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
 
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
 
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
 
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
 
const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 200001;
 
int n, ans;
vpi adj[MX];
pi ret[MX], oops[MX];

vpi genPre(vector<array<int,3>> v) {
    vpi V;
    int fst = 0, mx = -MOD;
    for (auto a: v) {
        fst += max(a[0],a[1]+a[2]);
        mx = max(mx,a[0]+a[2]-max(a[0],a[1]+a[2]));
        V.pb({fst,mx});
    }
    return V;
}

pi eval(vector<array<int,3>> v) {
    if (sz(v) == 0) return {0,-MOD};
    pi a = genPre(v).back(); a.s += a.f;
    return a;
}

void dfs(int cur, int pre) {
    vector<array<int,3>> v;
    for (auto a: adj[cur]) if (a.f != pre) {
        dfs(a.f,cur); 
        v.pb({ret[a.f].f,ret[a.f].s,a.s});
    }
    ret[cur] = eval(v);
}
 
vpi genSuf(vector<array<int,3>> v) {
    reverse(all(v));
    auto a = genPre(v);
    reverse(all(a));
    return a;
}

void dfs2(int cur, int pre) {
    vector<array<int,3>> v;
    for (auto a: adj[cur]) {
        if (a.f != pre) v.pb({ret[a.f].f,ret[a.f].s,a.s});
        else v.pb({oops[cur].f,oops[cur].s,a.s});
    }
    
    vpi L = genPre(v), R = genSuf(v);
    
    ans = max(ans,L.back().f);
    // if (cur == 1) cout << "HI " << ans << "\n";
    
    int i = 0;
    for (auto a: adj[cur]) {
        if (a.f != pre) {
            oops[a.f].f = (i == 0 ? 0 : L[i-1].f)+(i == sz(R)-1 ? 0 : R[i+1].f);
            oops[a.f].s = oops[a.f].f+max(i == 0 ? -MOD : L[i-1].s,i == sz(R)-1 ? -MOD : R[i+1].s);
            dfs2(a.f,cur);
        }
        i ++;
    }
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n;
    F0R(i,n-1) {
        int a,b,c; cin >> a >> b >> c;
        adj[a].pb({b,c}), adj[b].pb({a,c});
    }
    dfs(1,0);
    dfs2(1,0);
    cout << ans;
}
 
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 5164 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 5 ms 4992 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 5164 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 5 ms 4992 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 6 ms 5120 KB Output is correct
15 Correct 6 ms 5120 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 5120 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 5120 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 5164 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 5 ms 4992 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 6 ms 5120 KB Output is correct
15 Correct 6 ms 5120 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 5120 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 5120 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct
23 Correct 10 ms 5376 KB Output is correct
24 Correct 11 ms 5376 KB Output is correct
25 Correct 11 ms 5376 KB Output is correct
26 Correct 17 ms 5632 KB Output is correct
27 Correct 15 ms 5632 KB Output is correct
28 Correct 13 ms 6256 KB Output is correct
29 Correct 13 ms 6016 KB Output is correct
30 Correct 13 ms 6000 KB Output is correct
31 Correct 16 ms 7088 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 5164 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 6 ms 5120 KB Output is correct
8 Correct 5 ms 4992 KB Output is correct
9 Correct 6 ms 5120 KB Output is correct
10 Correct 6 ms 5120 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 6 ms 5120 KB Output is correct
15 Correct 6 ms 5120 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 5120 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 5120 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct
23 Correct 10 ms 5376 KB Output is correct
24 Correct 11 ms 5376 KB Output is correct
25 Correct 11 ms 5376 KB Output is correct
26 Correct 17 ms 5632 KB Output is correct
27 Correct 15 ms 5632 KB Output is correct
28 Correct 13 ms 6256 KB Output is correct
29 Correct 13 ms 6016 KB Output is correct
30 Correct 13 ms 6000 KB Output is correct
31 Correct 16 ms 7088 KB Output is correct
32 Correct 69 ms 7764 KB Output is correct
33 Correct 75 ms 7800 KB Output is correct
34 Correct 76 ms 7764 KB Output is correct
35 Correct 378 ms 15736 KB Output is correct
36 Correct 383 ms 15736 KB Output is correct
37 Correct 375 ms 15736 KB Output is correct
38 Correct 253 ms 27740 KB Output is correct
39 Correct 248 ms 24500 KB Output is correct
40 Correct 265 ms 23268 KB Output is correct
41 Correct 394 ms 32032 KB Output is correct