Submission #460589

#	Time	Username	Problem	Language	Result	Execution time	Memory
460589		idas	Cheap flights (LMIO18_pigus_skrydziai)	C++11	0 / 100	527 ms	37800 KiB

pigus_skrydziai

#include <bits/stdc++.h>
#define FOR(i, begin, end) for(int i = (begin); i < (end); i++)
#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr)
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define SZ(x) ((int)((x).size()))
#define LE(vec) vec[vec.size()-1]
#define TSTS int t; cin >> t; while(t--)solve()

const int INF = 1e9;
const long long LINF = 1e18;
const long double PI = asin(1)*2;
const int MOD = 1e9+7;

using namespace std;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef map<int, int> mii;
typedef long long ll;
typedef long double ld;

void setIO()
{
    FAST_IO;
}

void setIO (string s)
 {
    setIO();
 	freopen((s+".in").c_str(),"r",stdin);
 	freopen((s+".out").c_str(),"w",stdout);
}

const int N=3e5+10, M=5e5+10;

int n, m, dp[N];
bool v[N];
ll cn[N], ans;
vi ad[N];
map<pii, ll> con;

void dfs(int u, int pst, int in)
{
    v[u]=true;
    for(auto it : ad[u]){
        if(!v[it]){
            dfs(it, u, in+1);
        }
        else{
            if(dp[it]==in-2){
                ll val=con[{min(pst, u), max(pst, u)}]
                +con[{min(it, u), max(it, u)}]
                +con[{min(it, pst), max(it, pst)}];
                ans=max(ans, val);
            }
        }
    }
}

int main()
{
    setIO();
    cin >> n >> m;
    FOR(i, 0, m)
    {
        int a, b, c;
        cin >> a >> b >> c;
        cn[a-1]+=c;
        cn[b-1]+=c;
        ad[a-1].PB(b-1);
        ad[b-1].PB(a-1);
        con[{min(a-1, b-1), max(a-1, b-1)}]=c;
    }

    FOR(i, 0, n)
    {
        ans=max(ans, cn[i]);
    }

    /*FOR(i, 0, n)
    {
        vector<pii> full;
        for(auto x : ad[i]){
            for(auto y : ad[x]){
                full.PB({y, x});
            }
        }

        sort(full.begin(), full.end());
        for(auto x : ad[i]){
            int l=0, r=(int)full.size()-1;
            while(l<r){
                int m=(l+r+1)/2;
                if(full[m].F<=x) l=m;
                else r=m-1;
            }

            if(full[l].F==x){
                //cout << i+1 << " " << x+1 << " " << full[l].S+1 << "\n";
                ll val=con[{min(i, x), max(i, x)}]
                +con[{min(x, full[l].S), max(x, full[l].S)}]
                +con[{min(i, full[l].S), max(i, full[l].S)}];
                ans=max(ans, val);
            }
        }
    }*/

    dfs(0, -1, 0);

    cout << ans;
}

Compilation message (stderr)

pigus_skrydziai.cpp: In function 'void setIO(std::string)':
pigus_skrydziai.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   freopen((s+".in").c_str(),"r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pigus_skrydziai.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |   freopen((s+".out").c_str(),"w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 25
• Subtask 3: 0 / 16
• Subtask 4: 0 / 47