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Submission #36804

# Submission time Handle Problem Language Result Execution time Memory
36804 2017-12-14T19:01:36 Z imaxblue Beads and wires (APIO14_beads) C++14
100 / 100
 212 ms 24308 KB 
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define pb push_back
#define x first
#define y second
#define pii pair<int, int>
#define p3i pair<pii, int>
#define pll pair<ll, ll>
#define p3l pair<pll, ll>
#define lseg L, (L+R)/2, N*2+1
#define rseg (L+R)/2+1, R, N*2+2
#define ub upper_bound
#define lb lower_bound
#define p_q priority_queue
#define MN 1000000009

ll dp[200005][5];
int n, a, b, d;
//Case 0: new branch/nothing
//Case 1: Going upwards
//Case 2: new branch, root below
//Case 3: Going upwards, root below
vector<pii> v[200005];
void dfs(int N, int P, int D){
    dp[N][2]=dp[N][3]=-(1 << 30);
    ll nxt=-(1 << 30); int o, o2;
    dp[N][0]=-(1 << 30);
    for (int l=0; l<v[N].size(); ++l){
        if (v[N][l].x==P) continue;
        dfs(v[N][l].x, N, v[N][l].y);

        dp[N][2]=max(dp[N][2], dp[N][0]+dp[v[N][l].x][2]-dp[v[N][l].x][0]);
        dp[N][2]=max(dp[N][2], dp[N][3]+dp[v[N][l].x][1]-dp[v[N][l].x][0]);

        if (dp[v[N][l].x][1]-dp[v[N][l].x][0]+D>dp[N][0]){
            nxt=dp[N][0];
            dp[N][0]=dp[v[N][l].x][1]-dp[v[N][l].x][0]+D;
        } else nxt=max(nxt, dp[v[N][l].x][1]-dp[v[N][l].x][0]+D);
        dp[N][1]+=dp[v[N][l].x][0];
        dp[N][2]=max(dp[N][2], dp[v[N][l].x][3]-dp[v[N][l].x][0]+D);
        dp[N][2]=max(dp[N][2], dp[v[N][l].x][2]-dp[v[N][l].x][0]-v[N][l].y+D);
        dp[N][3]=max(dp[N][3], dp[v[N][l].x][2]-dp[v[N][l].x][0]+D);
    }
    dp[N][2]=max(dp[N][2], dp[N][0]+nxt-D);
    dp[N][2]+=dp[N][1];
    dp[N][0]=max(0LL, dp[N][0]);
    dp[N][0]+=dp[N][1];
    dp[N][3]+=dp[N][1];
    dp[N][1]+=D;
    /*cout << N << ": ";
    for (int l=0; l<4; ++l){
        cout << dp[N][l] << ' ';
    }
    cout << endl;*/
}
int main(){
    scanf("%i", &n);
    for (int l=0; l<n-1; ++l){
        scanf("%i%i%i", &a, &b, &d);
        v[a].pb(mp(b, d));
        v[b].pb(mp(a, d));
    }
    dfs(1, -1, 0);
    cout << max(dp[1][1], dp[1][2]);
    return 0;
}

Compilation message

beads.cpp: In function 'void dfs(int, int, int)':
beads.cpp:30:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int l=0; l<v[N].size(); ++l){
                   ~^~~~~~~~~~~~
beads.cpp:28:28: warning: unused variable 'o' [-Wunused-variable]
     ll nxt=-(1 << 30); int o, o2;
                            ^
beads.cpp:28:31: warning: unused variable 'o2' [-Wunused-variable]
     ll nxt=-(1 << 30); int o, o2;
                               ^~
beads.cpp: In function 'int main()':
beads.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i", &n);
     ~~~~~^~~~~~~~~~
beads.cpp:61:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%i%i%i", &a, &b, &d);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 18 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 7 ms 4992 KB Output is correct
7 Correct 6 ms 5028 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 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 5 ms 4992 KB Output is correct
2 Correct 18 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 7 ms 4992 KB Output is correct
7 Correct 6 ms 5028 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 5 ms 4992 KB Output is correct
16 Correct 5 ms 4992 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 5 ms 4992 KB Output is correct
2 Correct 18 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 7 ms 4992 KB Output is correct
7 Correct 6 ms 5028 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 5 ms 4992 KB Output is correct
16 Correct 5 ms 4992 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 8 ms 5376 KB Output is correct
24 Correct 9 ms 5376 KB Output is correct
25 Correct 9 ms 5404 KB Output is correct
26 Correct 11 ms 5760 KB Output is correct
27 Correct 10 ms 5760 KB Output is correct
28 Correct 11 ms 5888 KB Output is correct
29 Correct 10 ms 5760 KB Output is correct
30 Correct 11 ms 5760 KB Output is correct
31 Correct 11 ms 6144 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 4992 KB Output is correct
2 Correct 18 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 7 ms 4992 KB Output is correct
7 Correct 6 ms 5028 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 5 ms 4992 KB Output is correct
16 Correct 5 ms 4992 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 8 ms 5376 KB Output is correct
24 Correct 9 ms 5376 KB Output is correct
25 Correct 9 ms 5404 KB Output is correct
26 Correct 11 ms 5760 KB Output is correct
27 Correct 10 ms 5760 KB Output is correct
28 Correct 11 ms 5888 KB Output is correct
29 Correct 10 ms 5760 KB Output is correct
30 Correct 11 ms 5760 KB Output is correct
31 Correct 11 ms 6144 KB Output is correct
32 Correct 36 ms 8788 KB Output is correct
33 Correct 40 ms 8892 KB Output is correct
34 Correct 36 ms 8952 KB Output is correct
35 Correct 200 ms 20344 KB Output is correct
36 Correct 199 ms 20472 KB Output is correct
37 Correct 208 ms 20360 KB Output is correct
38 Correct 145 ms 20684 KB Output is correct
39 Correct 141 ms 20696 KB Output is correct
40 Correct 172 ms 20548 KB Output is correct
41 Correct 212 ms 24308 KB Output is correct