oj.uz

Submission #166535

# Submission time Handle Problem Language Result Execution time Memory
166535 2019-12-02T17:43:51 Z combi1k1 Beads and wires (APIO14_beads) C++14
100 / 100
 242 ms 25156 KB 
#include<bits/stdc++.h>

using namespace std;

#define pb  emplace_back

#define int long long

const int   N   = 2e5 + 1;

typedef pair<int,int>   ii;

vector<ii>  g[N];

int f[N][2];
int ans = 0;

void dfs(int u,int p)   {
    int mx = -1e9;
    for(ii  e : g[u])   {
        int v = e.first;
        int c = e.second;
        if (v == p) continue;
        dfs(v,u);

        f[u][0] += max(f[v][1] + c,f[v][0]);

        if (mx < min(c,f[v][0] - f[v][1]))
            mx = min(c,f[v][0] - f[v][1]);
    }
    f[u][1] = f[u][0] + mx;
}
void cal(int u,int p,int lz)    {
    ans = max(ans,f[u][0]);

    int Sum = f[u][0];
    int mx1 = lz;
    int mx2 = -1e9;

    for(ii  e : g[u])   {
        int v = e.first;
        int c = e.second;
        if (v ^ p)  {
            if (mx2 < min(c,f[v][0] - f[v][1]))
                mx2 = min(c,f[v][0] - f[v][1]);
            if (mx1 < mx2)
                swap(mx1,mx2);
        }
    }
    for(ii  e : g[u])   {
        int v = e.first;
        int c = e.second;
        if (v ^ p)  {
            int prv = max(f[v][1] + c,f[v][0]);
            int cur = min(c,f[v][0] - f[v][1]);

            if (cur ^ mx1)
                cur = mx2;

            cur = mx1 + mx2 - cur;

            Sum -= prv; //now Sum is equal to f[u][0] when we start dfs from node v

            f[v][0] += max(cur + c,0ll) + Sum;
            f[v][1]  = max(cur + f[v][0],f[v][1]);

            cal(v,u,min(c,-cur));
            Sum += prv;
        }
    }
}

signed main()   {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int n;  cin >> n;

    for(int i = 1 ; i < n ; ++i)    {
        int x;  cin >> x;
        int y;  cin >> y;
        int c;  cin >> c;
        g[x].pb(y,c);
        g[y].pb(x,c);
    }

    dfs(1,0);
    cal(1,0,-1e9);

    cout << ans << endl;
}
/*
5
1 2 10
1 3 40
1 4 15
1 5 20
*/

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5112 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 7 ms 4984 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 7 ms 4984 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5112 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 7 ms 4984 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 7 ms 4984 KB Output is correct
13 Correct 7 ms 5112 KB Output is correct
14 Correct 6 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 7 ms 4984 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 7 ms 4984 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 4984 KB Output is correct
21 Correct 7 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5112 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 7 ms 4984 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 7 ms 4984 KB Output is correct
13 Correct 7 ms 5112 KB Output is correct
14 Correct 6 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 7 ms 4984 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 7 ms 4984 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 4984 KB Output is correct
21 Correct 7 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 9 ms 5368 KB Output is correct
24 Correct 9 ms 5496 KB Output is correct
25 Correct 10 ms 5372 KB Output is correct
26 Correct 15 ms 5880 KB Output is correct
27 Correct 13 ms 5880 KB Output is correct
28 Correct 12 ms 5752 KB Output is correct
29 Correct 11 ms 5880 KB Output is correct
30 Correct 11 ms 5880 KB Output is correct
31 Correct 15 ms 6136 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5112 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 7 ms 4984 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 7 ms 4984 KB Output is correct
13 Correct 7 ms 5112 KB Output is correct
14 Correct 6 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 7 ms 4984 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 7 ms 4984 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 4984 KB Output is correct
21 Correct 7 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 9 ms 5368 KB Output is correct
24 Correct 9 ms 5496 KB Output is correct
25 Correct 10 ms 5372 KB Output is correct
26 Correct 15 ms 5880 KB Output is correct
27 Correct 13 ms 5880 KB Output is correct
28 Correct 12 ms 5752 KB Output is correct
29 Correct 11 ms 5880 KB Output is correct
30 Correct 11 ms 5880 KB Output is correct
31 Correct 15 ms 6136 KB Output is correct
32 Correct 45 ms 9336 KB Output is correct
33 Correct 44 ms 9336 KB Output is correct
34 Correct 47 ms 9208 KB Output is correct
35 Correct 242 ms 22008 KB Output is correct
36 Correct 233 ms 21948 KB Output is correct
37 Correct 237 ms 21988 KB Output is correct
38 Correct 151 ms 21340 KB Output is correct
39 Correct 151 ms 21072 KB Output is correct
40 Correct 163 ms 21336 KB Output is correct
41 Correct 217 ms 25156 KB Output is correct