oj.uz

Submission #107409

# Submission time Handle Problem Language Result Execution time Memory
107409 2019-04-24T06:24:38 Z shoemakerjo Designated Cities (JOI19_designated_cities) C++14
33 / 100
 1018 ms 54000 KB 
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
const int maxn = 200010;
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pil pair<int, pll>
#define pli pair<ll, int>
#define mp make_pair

int n, q;

//we want the seg-tree to go in euler tour order
int qus[maxn];
vector<pil> adj[maxn];

ll ans[maxn]; //store ans for each value
ll dep[maxn]; //distance from root to me
int par[maxn];
ll plink[maxn];
ll pplink[maxn];

int rt; //some global root variable
ll esum = 0LL; //total edge sum
//barebones dfs
void dfs(int u, int p = -1) {
  if (p == -1) {
    dep[u] = 0LL;
    par[u] = -1;
    plink[u] = 0LL;
  }
  for (pil vp : adj[u]) {
    if (vp.first == p) continue;
    dep[vp.first] = dep[u] + vp.second.first; //dep is length to bot
    par[vp.first] = u;
    plink[vp.first] = vp.second.second;
    pplink[vp.first] = vp.second.first;
    dfs(vp.first, u);
  }
}

void dfs1(int u, ll msum = 0LL) {
  ans[1] = min(ans[1], esum - msum);
  for (pil vp : adj[u]) {
    if (vp.first != par[u]) {
      dfs1(vp.first, msum - vp.second.second +
        vp.second.first);
    }
  }
}

void go1() {
  //finds the answer for 1 by itself
  //when I go to a child, I reverse that edge
  //start with all going down
  ans[1] = esum;
  ll csum = 0LL;
  for (int i = 1; i <= n; i++) {
    if (i != rt) csum += plink[i];
  }
  dfs1(rt, csum);
}

pli mdepth[maxn]; //want maxdepth

pii cg;

void dfs2(int u, ll msum) {
  //msum is the sum of everything in
  //consider me to be an lca
  mdepth[u] = {dep[u], u};
  vector<pli> ops;

  for (pil vp : adj[u]) {
    if (vp.first == par[u]) continue;
    dfs2(vp.first, msum - vp.second.second);
    ops.push_back(mdepth[vp.first]);
  }

  sort(ops.begin(), ops.end());
  reverse(ops.begin(), ops.end());
  if (ops.size()) mdepth[u] = ops[0];
  if (ops.size() < 2) return;
  msum += ops[0].first + ops[1].first - dep[u];
  if (esum - msum < ans[2]) {
    ans[2] = esum - msum;
    cg = mp(ops[0].second, ops[1].second);
  }
}

pii go2() {
  //we  consider everything as the lca
  //then we sacrifice a certain amount that "goes down"
  //start with all of the par-links in (par points up)
  ans[2] = esum;
  //   we lose some of the par-links
  ll csum = 0LL;
  for (int i = 1; i <= n; i++) {
    if (i != rt) csum += plink[i];
  }
  dfs2(rt, csum);
  return cg;
}

int st[maxn];
int en[maxn];
vector<int> stuff;

void etour(int u) {
  st[u] = stuff.size();
  stuff.push_back(u);
  for (pil vp : adj[u]) {
    if (vp.first != par[u]) {
      etour(vp.first);
    }
  }
  en[u] = stuff.size()-1;
}

pli seg[maxn*4]; //a max seg tree
ll lazy[maxn*4];

void delaze(int ss, int se, int si) {
  seg[si] = mp(seg[si].first + lazy[si], seg[si].second);
  if (lazy[si] && ss != se) {
    lazy[si*2+1] += lazy[si];
    lazy[si*2+2] += lazy[si];
  }
  lazy[si] = 0;
}

pli query() {
  //get the maximum
  delaze(0, n-1, 0);
  return seg[0];
}

void upd(int us, int ue, ll diff, int ss = 0, int se = n-1,
    int si = 0) {
  delaze(ss, se, si);
  if (us > ue || ss > se || us > se || ue < ss) return;
  if (us <= ss && se <= ue) {
    lazy[si] += diff;
    delaze(ss, se, si);
    return;
  }
  int mid = (ss+se)/2;
  upd(us, ue, diff, ss, mid, si*2+1);
  upd(us, ue, diff, mid+1, se, si*2+2);
  seg[si] = max(seg[si*2+1], seg[si*2+2]);
}

bool isrem[maxn];

void buildtree(int ss = 0, int se  = n-1, int si = 0) {
  if (ss == se) {
    seg[si] = {dep[stuff[ss]], stuff[ss]};
    return;
  }
  int mid = (ss+se)/2;
  buildtree(ss, mid, si*2+1);
  buildtree(mid+1, se, si*2+2);
  seg[si] = max(seg[si*2+1], seg[si*2+2]);
}

void proc(int u) {
  //remove this node
  //go up the parents list
  //all children of me lose going up (keep doing this)
  while (!isrem[u]) {
    // cout << " ----- " << u << endl;
    isrem[u] = true;
    upd(st[u], en[u], 0-pplink[u]);
    u = par[u];
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n;
  int a, b;
  ll c, d;
  for (int i = 0; i < n-1; i++) {
    cin >> a >> b >> c >> d;
    adj[a].emplace_back(b, mp(c, d));
    adj[b].emplace_back(a, mp(d, c));
    esum += c;
    esum += d;
  }
  cin >> q;
  for (int i = 1; i <= q; i++) {
    cin >> qus[i];
  }
  if (n == 2) {
    //just bash
    for (int i = 1; i <= q; i++) {
      if (qus[i] == 2) {
        cout << 0 << endl;
      }
      else {
        cout << min(adj[1][0].second.first,
          adj[1][0].second.second);
      }
    }
    return 0;
  }
  //now we want to root at a non-leaf
  rt = 1;
  for (int i = 2; i <= n; i++) {
    if (adj[i].size() != 1) rt = i;
  }
  dfs(rt);

  go1();
  pii vp = go2();

  // cout << "got 2 : " << vp.first << " " << vp.second << endl;
  //we get the two guys
  rt = par[vp.first];
  dfs(rt); //reset everything (yea)
  etour(rt);
  // cout << "done the dfs" << endl;

  ll cans = ans[2]; //starting answer (will increase)
  //now we do the greedy thing
  buildtree(); //just start all as it is

  // cout << "built the tree" << endl;

  isrem[rt] = true; //basically is removed
  proc(vp.first);
  proc(vp.second);

  for (int i = 3; i <= n; i++) {
    pli tmp = query();
    if (tmp.first != 0) {
      cans -= tmp.first;
      proc(tmp.second);
      // cout << "removing " << tmp.second << " "
      //   << tmp.first << endl;
    }
    else {
      assert(cans == 0LL);
    }
    ans[i] = cans;
  }

  //now we are just printing out answer (for now - 1/2)
  for (int i = 1; i <= q; i++) {
    cout << ans[qus[i]] << '\n';
  }
  cout.flush();
}

//calculate the answer for one
//use a dp to calculate the answer for two (root at non-leaf)
//greedily add nodes until we get to each val (if none left - do nothing)

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Incorrect 7 ms 4992 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 775 ms 43272 KB Output is correct
3 Correct 999 ms 52840 KB Output is correct
4 Correct 712 ms 43492 KB Output is correct
5 Correct 737 ms 44148 KB Output is correct
6 Correct 810 ms 45184 KB Output is correct
7 Correct 694 ms 43240 KB Output is correct
8 Correct 895 ms 54000 KB Output is correct
9 Correct 592 ms 44480 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 784 ms 43416 KB Output is correct
3 Correct 903 ms 52980 KB Output is correct
4 Correct 748 ms 43604 KB Output is correct
5 Correct 727 ms 44196 KB Output is correct
6 Correct 850 ms 45300 KB Output is correct
7 Correct 691 ms 44640 KB Output is correct
8 Correct 864 ms 52712 KB Output is correct
9 Correct 538 ms 44536 KB Output is correct

Subtask #4
0 / 17.0

# Verdict Execution time Memory Grader output
1 Incorrect 7 ms 4992 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 775 ms 43272 KB Output is correct
3 Correct 999 ms 52840 KB Output is correct
4 Correct 712 ms 43492 KB Output is correct
5 Correct 737 ms 44148 KB Output is correct
6 Correct 810 ms 45184 KB Output is correct
7 Correct 694 ms 43240 KB Output is correct
8 Correct 895 ms 54000 KB Output is correct
9 Correct 592 ms 44480 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 784 ms 43416 KB Output is correct
12 Correct 903 ms 52980 KB Output is correct
13 Correct 748 ms 43604 KB Output is correct
14 Correct 727 ms 44196 KB Output is correct
15 Correct 850 ms 45300 KB Output is correct
16 Correct 691 ms 44640 KB Output is correct
17 Correct 864 ms 52712 KB Output is correct
18 Correct 538 ms 44536 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 824 ms 43576 KB Output is correct
21 Correct 823 ms 52972 KB Output is correct
22 Correct 748 ms 43484 KB Output is correct
23 Correct 836 ms 44016 KB Output is correct
24 Correct 823 ms 43888 KB Output is correct
25 Correct 988 ms 43904 KB Output is correct
26 Correct 1018 ms 43880 KB Output is correct
27 Correct 896 ms 43344 KB Output is correct
28 Correct 861 ms 45388 KB Output is correct
29 Correct 904 ms 44268 KB Output is correct
30 Correct 778 ms 44160 KB Output is correct
31 Correct 716 ms 43080 KB Output is correct
32 Correct 946 ms 52040 KB Output is correct
33 Correct 666 ms 44500 KB Output is correct

Subtask #6
0 / 44.0

# Verdict Execution time Memory Grader output
1 Incorrect 7 ms 4992 KB Output isn't correct
2 Halted 0 ms 0 KB -