Submission #1041835

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041835		MMihalev	Beads and wires (APIO14_beads)	C++14	28 / 100	1043 ms	860 KiB

beads

#include<iostream>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<tuple>
#include<set>
#include<map>
#include<random>
#include<chrono>
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("fast-math")
#pragma GCC optimize("vpt")
#pragma GCC optimize("rename-registers")
#pragma GCC optimize("move-loop-invariants")
#pragma GCC optimize("unswitch-loops")
#pragma GCC optimize("branch-target-load-optimize2")
#pragma GCC optimize("btr-bb-exclusive")
using namespace std;
const short MAX_N=1e4+1;
const int INF=2e9+1e8;
int dp[MAX_N][2];
short n;
vector<pair<short,short>>g[MAX_N];
void reset()
{
    for(short i=1;i<=n;i++)
    {
        dp[i][0]=0;
        dp[i][1]=-INF;
    }
}
void dfs(short u,short par)
{
    int sum=0,cur;

    for(auto& [v,edge]:g[u])
    {
        if(v==par)continue;
        dfs(v,u);

        sum+=max(edge+dp[v][1],dp[v][0]);
    }

    for(auto& [v,edge]:g[u])
    {
        if(v==par)continue;

        cur=max(edge+dp[v][1],dp[v][0]);
        dp[u][1]=max(dp[u][1],sum-cur+edge+dp[v][0]);
    }
    dp[u][0]=sum;
}
signed main ()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>n;
    for(short i=1;i<n;i++)
    {
        short u,v,c;
        cin>>u>>v>>c;
        g[u].push_back({v,c});
        g[v].push_back({u,c});
    }
    int ans=0;
    for(short i=1;i<=n;i++)
    {
        reset();
        dfs(i,0);
        ans=max(ans,dp[i][0]);
    }
    cout<<ans<<"\n";
    return 0;
}

Compilation message (stderr)

beads.cpp:22:52: warning: bad option '-fbranch-target-load-optimize2' to pragma 'optimize' [-Wpragmas]
   22 | #pragma GCC optimize("branch-target-load-optimize2")
      |                                                    ^
beads.cpp:23:40: warning: bad option '-fbtr-bb-exclusive' to pragma 'optimize' [-Wpragmas]
   23 | #pragma GCC optimize("btr-bb-exclusive")
      |                                        ^
beads.cpp:30:12: warning: bad option '-fbranch-target-load-optimize2' to attribute 'optimize' [-Wattributes]
   30 | void reset()
      |            ^
beads.cpp:30:12: warning: bad option '-fbtr-bb-exclusive' to attribute 'optimize' [-Wattributes]
beads.cpp:38:27: warning: bad option '-fbranch-target-load-optimize2' to attribute 'optimize' [-Wattributes]
   38 | void dfs(short u,short par)
      |                           ^
beads.cpp:38:27: warning: bad option '-fbtr-bb-exclusive' to attribute 'optimize' [-Wattributes]
beads.cpp: In function 'void dfs(short int, short int)':
beads.cpp:42:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   42 |     for(auto& [v,edge]:g[u])
      |               ^
beads.cpp:50:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   50 |     for(auto& [v,edge]:g[u])
      |               ^
beads.cpp: At global scope:
beads.cpp:59:14: warning: bad option '-fbranch-target-load-optimize2' to attribute 'optimize' [-Wattributes]
   59 | signed main ()
      |              ^
beads.cpp:59:14: warning: bad option '-fbtr-bb-exclusive' to attribute 'optimize' [-Wattributes]

• Subtask 1: 13 / 13
• Subtask 2: 15 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43