Submission #414098

#	Time	Username	Problem	Language	Result	Execution time	Memory
414098		cpp219	Evacuation plan (IZhO18_plan)	C++14	100 / 100	2091 ms	41784 KiB

plan

#pragma GCC optimization "O2"
#pragma GCC optimization "unroll-loop"
#pragma GCC target ("avx2")

#include <bits/stdc++.h>
#define ll int
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 1e5 + 9;
const ll Log2 = 20;
const ll inf = 1e9 + 7;
typedef pair<ll,ll> LL;
vector<LL> g[N];
ll n,m,x,y,w,k,d[N],pos[N];

priority_queue<LL,vector<LL>,greater<LL>> pq;

void Dij(){
    while(!pq.empty()){
        LL t = pq.top(); pq.pop();
        ll u = t.sc,val = t.fs;
        for (auto i : g[u]){
            ll v = i.fs,L = i.sc;
            if (d[v] > val + L){
                d[v] = val + L; pq.push({d[v],v});
            }
        }
    }
}

bool lf(ll x,ll y){
    return d[x] > d[y];
}

ll lab[N];
ll Find(ll u){
    if (lab[u] < 0) return u;
    return lab[u] = Find(lab[u]);
}

void Union(ll p,ll q){
    ll r = Find(p),s = Find(q);
    if (r == s) return;
    if (lab[r] > lab[s]) swap(r,s);
    lab[r] += lab[s]; lab[s] = r;
}
LL q[N];
ll l[N],h[N],was[N],Q;
vector<ll> v[N];
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define task "test"
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        //freopen(task".out", "w", stdout);
    }
    cin>>n>>m;
    for (ll i = 1;i <= m;i++){
        cin>>x>>y>>w;
        g[x].push_back({y,w}); g[y].push_back({x,w});
    }
    for (ll i = 1;i <= n;i++){
        d[i] = inf; pos[i] = i;
    }
    cin>>k;
    for (ll i = 1;i <= k;i++) cin>>x,d[x] = 0,pq.push({0,x});
    Dij(); sort(pos + 1,pos + n + 1,lf);
    cin>>Q;
    for (ll i = 1;i <= Q;i++) cin>>q[i].fs>>q[i].sc,l[i] = 1,h[i] = n;
    for (ll i = 1;i <= 45;i++){
        memset(lab,-1,sizeof(lab)); memset(was,0,sizeof(was));
        for (ll j = 1;j <= n;j++) v[j].clear();
        for (ll j = 1;j <= Q;j++){
            if (l[j] > h[j]) continue;
            ll mid = (l[j] + h[j]) / 2;
            v[mid].push_back(j);
        }
        for (ll j = 1;j <= n;j++){
            ll now = pos[j]; was[now] = 1;
            for (auto k : g[now]) if (was[k.fs]) Union(now,k.fs);
            for (auto k : v[j]){
                if (Find(q[k].fs) == Find(q[k].sc)) h[k] = j - 1;
                else l[k] = j + 1;
            }
        }
    }
    for (ll i = 1;i <= Q;i++){
        ll now = pos[l[i]];
        cout<<d[now]<<"\n";
    }
}

Compilation message (stderr)

plan.cpp:1: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    1 | #pragma GCC optimization "O2"
      | 
plan.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization "unroll-loop"
      | 
plan.cpp: In function 'int main()':
plan.cpp:57:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46