Submission #486517

#	Time	Username	Problem	Language	Result	Execution time	Memory
486517		MohamedAliSaidane	Dreaming (IOI13_dreaming)	C++14	Compilation error	0 ms	0 KiB

dreaming

#include <bits/stdc++.h>
using namespace std;

typedef vector<int> vi;
typedef long long ll;
typedef vector<ll> vll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef long double ld;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

#define pb push_back
#define popb pop_back
#define all(v) (v).begin(),(v).end()
#define ff first
#define ss second

const ll MOD = 1e9 + 7;
const ll INF = 1e18;

//          SOLUTION             \\

const int MAX_N = 1e5 + 4;

int n, m, l;
vpi adj[MAX_N];
vi p, rnk;
vi wt;
vi comps;
vpi cost[MAX_N];
int parent[MAX_N];
bitset<MAX_N> visited;
int d[MAX_N];
int findset(int x){ return p[x]== x? x: findset(p[x]);}
void unite(int i, int j)
{
    int x= findset(i);
    int y = findset(j);
    if(x == y)
        return ;
    if(rnk[x] > rnk[y])
        swap(x,y);
    if(rnk[x] == rnk[y])
        rnk[y]++;
    p[x] = y;
    return ;
}
void solve()
{
    cin >> n >> m >> l;
    p.assign(n,0); rnk.assign(n,0);
    wt.assign(n,0);
    int maxt = 0;
    for(int i= 0; i <n; i ++)
        p[i]= i ;
    for(int i=  1; i <= m; i ++)
    {
        int a, b, w;
        cin >> a >> b >> w;
        adj[a].pb({b,w});
        adj[b].pb({a,w});
        unite(a,b);
    }
    for(int i = 0; i <n; i ++)
    {
        int x= findset(i);
        if(visited[x])
            continue;
        visited[x] = 1;
        unordered_set<int> seen;
        set<pii> s;
        s.insert({0,x});
        seen.insert(x);
        int ed =  x;
        while(!s.empty())
        {
            pii u = *(s.begin());
            s.erase(s.begin());
            int node = u.ss;
            int dis = u.ff;
            for(auto e: adj[node])
            {
                if(seen.count(e.ff) != 0)
                    continue;
                seen.insert(e.ff);
                s.insert({dis+e.ss,e.ff});
            }
            if(s.empty())
                ed = node;
        }
        int lgest = 0;
        s.clear(); seen.clear();
        s.insert({0,ed});
        int cent = x;
        seen.insert(ed);
        int mint = MOD;
        while(!s.empty())
        {
            pii u = *(s.begin());
            s.erase(s.begin());
            int node = u.ss;
            int dis = u.ff;
            for(auto e: adj[node])
            {
                if(seen.count(e.ff) != 0)
                    continue;
                seen.insert(e.ff);
                s.insert({dis + e.ss,e.ff});
            }
            if(s.empty())
                lgest = dis;
        }
        s.clear(); seen.clear();
        s.insert({0,ed});
        seen.insert(ed);
        parent[ed]= -1;
        int st = x;
        while(!s.empty())
        {
            pii u = *(s.begin());
            s.erase(s.begin());
            int node = u.ss;
            int dis = u.ff;
            d[node] = dis;
            for(auto e: adj[node])
            {
                if(seen.count(e.ff) != 0)
                    continue;
                seen.insert(e.ff);
                parent[e.ff] = node;
                s.insert({dis + e.ss,e.ff});
            }
            if(dis == lgest)
            {
                st = node;
                break;
            }
        }
        int u = st;
        maxt = max(maxt,lgest);
        while(u != -1)
        {
            int cst = max(d[u],lgest-d[u]);
            if(cst < mint)
            {
                mint = cst;
                cent = u;
            }
            u = parent[u];
        }
        comps.pb(mint);
    }
    sort(all(comps));
    reverse(all(comps));
    if(m <= n-3)
        maxt = max(maxt,comps[1]+comps[2]+l+l);
    if(m <= n-2)
        maxt = max(maxt,comps[0]+comps[1]+l);
    cout << maxt;

}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int tt = 1;
    while(tt--)
    {
        solve();
    }
}

Compilation message (stderr)

dreaming.cpp:22:1: warning: multi-line comment [-Wcomment]
   22 | //          SOLUTION             \\
      | ^
dreaming.cpp: In function 'void solve()':
dreaming.cpp:95:13: warning: variable 'cent' set but not used [-Wunused-but-set-variable]
   95 |         int cent = x;
      |             ^~~~
/usr/bin/ld: /tmp/cct9YIR3.o: in function `main':
dreaming.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccfeUWS3.o:grader.c:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccfeUWS3.o: in function `main':
grader.c:(.text.startup+0xd1): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status