Submission #167426

#	Time	Username	Problem	Language	Result	Execution time	Memory
167426		muhammad_hokimiyon	Evacuation plan (IZhO18_plan)	C++14	100 / 100	863 ms	43080 KiB

plan

#include <bits/stdc++.h>

//#pragma GCC optimize("Ofast")

#define fi first
#define se second
#define ll long long

using namespace std;

const int N = 1e5 + 7;
const int mod = 1e9 + 7;

int n,m,q,k;
int l = 1;
int cnt;
int a[N];
int d[N];
int p[N];
int tin[N];
int dep[N];
int tout[N];
bool used[N];
vector < int > g[N];
vector < vector < int > > up;
vector < pair < int , int > > v[N];

int get( int x )
{
    return (x == p[x] ? x : p[x] = get(p[x]));
}

void dfs( int x , int p )
{
    tin[x] = ++cnt;
    up[x][0] = p;
    for( int i = 1; i <= l; i++ ){
        up[x][i] = up[up[x][i - 1]][i - 1];
    }
    for( auto y : g[x] ){
        if( y != p ){
            dep[y] = dep[x] + 1;
            dfs(y , x);
        }
    }
    tout[x] = cnt;
}

bool upper( int x , int y )
{
    return (tin[x] <= tin[y] && tout[x] >= tout[y]);
}

int lca( int x , int y )
{
    if( upper(x , y) )return x;
    if( upper(y , x) )return y;
    for( int i = l; i >= 0; i-- ){
        if( !upper(up[x][i] , y) ){
            x = up[x][i];
        }
    }
    return up[x][0];
}

void solve()
{
    cin >> n >> m;
    while( (1 << l) <= n )l++;
    up.resize(n + 10);
    for( int i = 0; i <= n; i++ ){
        up[i].resize(l + 10);
        p[i] = i;
        d[i] = 1e9;
    }
    for( int i = 1; i <= m; i++ ){
        int x,y,z;
        cin >> x >> y >> z;
        v[x].push_back({y , z});
        v[y].push_back({x , z});
    }
    set < pair < int , int > > s;
    cin >> k;
    for( int i = 1; i <= k; i++ ){
        int x;
        cin >> x;
        d[x] = 0;
        s.insert({0 , x});
    }
    while( !s.empty() ){
        auto x = s.begin()->se;
        s.erase(s.begin());
        for( auto y : v[x] ){
            if( d[x] + y.se < d[y.fi] ){
                s.erase({d[y.fi] , y.fi});
                d[y.fi] = d[x] + y.se;
                s.insert({d[y.fi] , y.fi});
            }
        }
    }
    vector < pair < int , int > > vv;
    for( int i = 1; i <= n; i++ ){
        vv.push_back({d[i] , i});
    }
    int start = 0;
    sort( vv.rbegin() , vv.rend() );
    for( auto y : vv ){
        used[y.se] = true;
        for( auto z : v[y.se] ){
            int xx = get(z.fi);
            int yy = y.se;
            if( used[z.fi] && xx != yy ){
                p[xx] = yy;
                g[yy].push_back(xx);
                g[xx].push_back(yy);
            }
        }
    }
    dfs(vv[n - 1].se , vv[n - 1].se);
    cin >> q;
    for( int i = 1; i <= q; i++ ){
        int x,y;
        cin >> x >> y;
        int c = lca(x , y);
        cout << d[c] << "\n";
    }
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen( "input.txt" , "r" , stdin );
    //freopen( "output.txt" , "w" , stdout );

    int t = 1;//cin >> t;
    while( t-- ){
        solve();
    }
}

Compilation message (stderr)

plan.cpp: In function 'void solve()':
plan.cpp:105:9: warning: unused variable 'start' [-Wunused-variable]
     int start = 0;
         ^~~~~

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