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답안 #208931

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
208931 2020-03-12T15:20:44 Z quocnguyen1012 통행료 (APIO13_toll) C++14
100 / 100
 2135 ms 14400 KB 
#include <bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back

using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> Edge;

const int maxn = 1e5 + 5;

int lab[maxn];
vector<Edge> rem, ed, mst;
vector<ii> add, adj[maxn];
int a[maxn], N, M, K, comp[maxn], cnt;
vector<int> tree[maxn];
int dep[maxn]; ii par[maxn];
ll sum[maxn], f[maxn];
int dp[maxn];

void init(int n)
{
  for(int i = 1; i <= n; ++i)
    lab[i] = -1;
}

int finds(int u)
{
  if(lab[u] < 0) return u;
  return lab[u] = finds(lab[u]);
}

bool merges(int u, int v)
{
  u = finds(u); v = finds(v);
  if(u == v) return false;
  if(lab[v] < lab[u]) swap(u, v);
  lab[u] += lab[v];
  lab[v] = u;
  return true;
}

void dfs(int u)
{
  comp[u] = cnt;
  sum[cnt] += a[u];
  for(int v : tree[u]){
    if(!comp[v]) dfs(v);
  }
}

void redfs(int u, int p = -1)
{
  f[u] = sum[u];
  for(auto v : adj[u]) if(v.fi != p){
    dep[v.fi] = dep[u] + 1;
    par[v.fi] = mp(u, v.se);
    redfs(v.fi, u);
    f[u] += f[v.fi];
  }
}

signed main(void)
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  if(fopen("A.INP", "r")){
    freopen("A.INP", "r", stdin);
    freopen("A.OUT", "w", stdout);
  }
  cin >> N >> M >> K;
  for(int i = 0; i < M; ++i){
    int u, v, w; cin >> u >> v >> w;
    ed.pb(mp(w, mp(u, v)));
  }
  for(int i = 0; i < K; ++i){
    int u, v; cin >> u >> v;
    add.pb(mp(u, v));
  }
  for(int i = 1; i <= N; ++i){
    cin >> a[i];
  }

  sort(ed.begin(), ed.end());
  init(N);
  for(auto & all : ed){
    int u = all.se.fi, v = all.se.se;
    if(merges(u, v)){
      mst.pb(all);
    }
  }
  init(N);
  for(auto & all : add){
    merges(all.fi, all.se);
  }
  for(auto & all : mst){
    int u = all.se.fi, v = all.se.se;
    if(merges(u, v)){
      tree[u].pb(v); tree[v].pb(u);
    }
    else{
      rem.pb(all);
    }
  }
  for(int i = 1; i <= N; ++i){
    if(!comp[i]){
      ++cnt;
      dfs(i);
    }
  }
  ll ans = 0;
  for(int mask = 0; mask < (1 << K); ++mask){
    init(cnt);
    bool ok = true;
    for(int i = 1; i <= cnt; ++i)
      adj[i].clear();
    for(int i = 0; i < K; ++i){
      if(mask >> i & 1){
        int u = comp[add[i].fi], v = comp[add[i].se];
        if(!merges(u, v)){
          ok = false;
          break;
        }
        dp[i + 1] = 1e9;
        adj[u].eb(v, i + 1); adj[v].eb(u, i + 1);
      }
    }
    if(ok == false) break;
    vector<Edge> tmp;
    for(auto & all : rem){
      int u = comp[all.se.fi], v = comp[all.se.se];
      if(merges(u, v)){
        adj[u].eb(v, 0);
        adj[v].eb(u, 0);
      }
      else{
        tmp.pb(all);
      }
    }
    dep[1] = 1;
    redfs(1, 1);
    for(auto & all : tmp){
      int u = comp[all.se.fi], v = comp[all.se.se], w = all.fi;
      if(dep[u] > dep[v]) swap(u, v);
			while(dep[u] < dep[v]){
				if(par[v].se != 0) dp[par[v].se] = min(dp[par[v].se], w);
				v = par[v].fi;
			}
			while(u != v){
				if(par[v].se != 0) dp[par[v].se] = min(dp[par[v].se], w);
				if(par[u].se != 0) dp[par[u].se] = min(dp[par[u].se], w);
				v = par[v].fi;
				u = par[u].fi;
			}
    }
    ll res = 0;
    for(int i = 0; i < K; ++i){
      if(mask >> i & 1){
        int u = add[i].fi, v = add[i].se;
        u = comp[u]; v = comp[v];
        if(dep[v] > dep[u]) swap(u, v);
        res += 1ll * dp[i + 1] * f[u];
      }
    }
    ans = max(ans, res);
  }
  cout << ans;
}

Compilation message

toll.cpp: In function 'int main()':
toll.cpp:71:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("A.INP", "r", stdin);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
toll.cpp:72:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("A.OUT", "w", stdout);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct

Subtask #2
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 10 ms 5112 KB Output is correct
4 Correct 8 ms 5112 KB Output is correct

Subtask #3
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 10 ms 5112 KB Output is correct
4 Correct 8 ms 5112 KB Output is correct
5 Correct 11 ms 5240 KB Output is correct
6 Correct 10 ms 5240 KB Output is correct

Subtask #4
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 10 ms 5112 KB Output is correct
4 Correct 8 ms 5112 KB Output is correct
5 Correct 11 ms 5240 KB Output is correct
6 Correct 10 ms 5240 KB Output is correct
7 Correct 230 ms 14400 KB Output is correct
8 Correct 247 ms 14172 KB Output is correct
9 Correct 232 ms 14168 KB Output is correct

Subtask #5
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 10 ms 5112 KB Output is correct
4 Correct 8 ms 5112 KB Output is correct
5 Correct 11 ms 5240 KB Output is correct
6 Correct 10 ms 5240 KB Output is correct
7 Correct 230 ms 14400 KB Output is correct
8 Correct 247 ms 14172 KB Output is correct
9 Correct 232 ms 14168 KB Output is correct
10 Correct 1645 ms 14192 KB Output is correct
11 Correct 2135 ms 14168 KB Output is correct
12 Correct 2133 ms 14168 KB Output is correct