Submission #940923

#	Time	Username	Problem	Language	Result	Execution time	Memory
940923		guagua0407	Capital City (JOI20_capital_city)	C++17	30 / 100	236 ms	20968 KiB

capital_city

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int mxn=2e5+5;
const int inf=1e9;
vector<int> adj[mxn];
bool visited[mxn];
int c[mxn];
vector<int> segtree(mxn*4,inf);
int n,k;

void update(int pos,int val,int l=1,int r=n,int v=1){
    if(l==r){
        segtree[v]=min(segtree[v],val);
        return;
    }
    int mid=(l+r)/2;
    if(pos<=mid) update(pos,val,l,mid,v*2);
    else update(pos,val,mid+1,r,v*2+1);
    segtree[v]=min(segtree[v*2],segtree[v*2+1]);
}

int query(int tl,int tr,int l=1,int r=n,int v=1){
    if(r<tl or tr<l){
        return inf;
    }
    if(tl<=l and r<=tr){
        return segtree[v];
    }
    int mid=(l+r)/2;
    return min(query(tl,min(mid,tr),l,mid,v*2),query(max(mid+1,tl),tr,mid+1,r,v*2+1));
}

int main() {_
    cin>>n>>k;
    for(int i=0;i<n-1;i++){
        int a,b;
        cin>>a>>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i=1;i<=n;i++){
        cin>>c[i];
        c[i]--;
    }
    int st;
    for(int i=1;i<=n;i++){
        if((int)adj[i].size()<=1) st=i;
    }
    vector<int> ord;
    ord.push_back(-1);
    queue<int> q;
    q.push(st);
    while(!q.empty()){
        int v=q.front();
        q.pop();
        visited[v]=true;
        ord.push_back(v);
        for(auto u:adj[v]){
            if(visited[u]) continue;
            q.push(u);
        }
    }
    vector<int> mnn(k),mxx(k);
    {
        vector<int> mn(k,inf),mx(k,-1);
        for(int i=1;i<ord.size();i++){
            mx[c[ord[i]]]=max(mx[c[ord[i]]],i);
            mn[c[ord[i]]]=min(mn[c[ord[i]]],i);
        }
        for(int i=1;i<ord.size();i++){
            int C=c[ord[i]];
            int val=query(mn[C],i);
            val=min(val,mn[C]);
            if(i==mx[C]){
                mnn[C]=val;
            }
            update(i,val);
        }
    }
    reverse(ord.begin()+1,ord.end());
    segtree=vector<int>(mxn*4,inf);
    {
        vector<int> mn(k,inf),mx(k,-1);
        for(int i=1;i<ord.size();i++){
            int C=c[ord[i]];
            mx[C]=max(mx[C],i);
            mn[C]=min(mn[C],i);
        }
        for(int i=1;i<ord.size();i++){
            int C=c[ord[i]];
            int val=query(mn[C],i);
            val=min(val,mn[C]);
            if(i==mx[C]){
                mxx[C]=val;
            }
            update(i,val);
        }
    }
    reverse(ord.begin()+1,ord.end());
    vector<int> mn(k,inf),mx(k,-1);
    for(int i=1;i<ord.size();i++){
        mx[c[ord[i]]]=max(mx[c[ord[i]]],i);
        mn[c[ord[i]]]=min(mn[c[ord[i]]],i);
    }
    for(int i=0;i<k;i++){
        mxx[i]=n-mxx[i]+1;
    }
    vector<int> pre(ord.size());
    for(int i=1;i<ord.size();i++){
        int C=c[ord[i]];
        pre[i]=pre[i-1];
        if(i==mx[C]){
            pre[i]++;
        }
    }
    int ans=inf;
    for(int i=0;i<k;i++){
        assert(mnn[i]>=1 and mnn[i]<=n and mxx[i]>=1 and mxx[i]<=n);
        ans=min(ans,pre[mxx[i]]-pre[mnn[i]-1]-1);
    }
    cout<<ans<<'\n';
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

capital_city.cpp: In function 'int main()':
capital_city.cpp:82:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |         for(int i=1;i<ord.size();i++){
      |                     ~^~~~~~~~~~~
capital_city.cpp:86:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |         for(int i=1;i<ord.size();i++){
      |                     ~^~~~~~~~~~~
capital_city.cpp:100:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |         for(int i=1;i<ord.size();i++){
      |                     ~^~~~~~~~~~~
capital_city.cpp:105:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |         for(int i=1;i<ord.size();i++){
      |                     ~^~~~~~~~~~~
capital_city.cpp:117:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |     for(int i=1;i<ord.size();i++){
      |                 ~^~~~~~~~~~~
capital_city.cpp:125:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |     for(int i=1;i<ord.size();i++){
      |                 ~^~~~~~~~~~~
capital_city.cpp: In function 'void setIO(std::string)':
capital_city.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
capital_city.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 1
• Subtask 2: 0 / 10
• Subtask 3: 30 / 30
• Subtask 4: 0 / 59