Submission #649959

#	Time	Username	Problem	Language	Result	Execution time	Memory
649959		enerelt14	Cats or Dogs (JOI18_catdog)	C++14	0 / 100	9 ms	11604 KiB

catdog

#include "catdog.h"
#include<bits/stdc++.h>
#define pb push_back
using namespace std;
const int MX=1e5+5;
int n, sz[MX], par[MX], num[MX];
int hldpar[MX], pos[MX], st[MX];
vector<int>adj[MX];
void dfs(int u, int pre){
    sz[u]=1;
    par[u]=pre;
    for (int i=0;i<adj[u].size();i++){
        int v=adj[u][i];
        if (v==pre)continue;
        dfs(v, u);
        sz[u]+=sz[v];
    }
}
void hld(int u, int pre){
    num[u]++;
    pos[u]=num[pre];
    hldpar[u]=pre;
    for (int i=0;i<adj[u].size();i++){
        int v=adj[u][i];
        if (v==par[u])continue;
        if (sz[v]*2>=sz[u])hld(v, pre);
        else hld(v, v);
    }
}
struct node{
    int a00, a01, a10, a11;
    friend node operator + (const node& a, const node& b){
        node c;
        c.a00=min(a.a00+b.a00, a.a01+b.a10);
        c.a01=min(a.a00+b.a01, a.a01+b.a11);
        c.a10=min(a.a10+b.a00, a.a11+b.a10);
        c.a11=min(a.a10+b.a01, a.a11+b.a11);
        return c;
    }
};
struct segtree{
    int s;
    vector<node>cost;
    segtree(){}
    segtree(int n){
        while(s<n)s*=2;
        cost.resize(2*s);
        for (int i=0;i<2*s;i++)cost[i].a01=cost[i].a10=1;
    }
    void update(int i, int& ch0, int& ch1){
        i+=s;
        cost[i].a00+=ch0;
        cost[i].a01+=ch0;
        cost[i].a10+=ch1;
        cost[i].a11+=ch1;
        i/=2;
        while(i!=0){
            cost[i]=cost[i*2]+cost[i*2+1];
            i/=2;
        }
    }
    void calc(int& x, int& y){
        x=min(cost[1].a00, cost[1].a01);
        y=min(cost[1].a10, cost[1].a11);
    }
} seg[MX];
void initialize(int N, vector<int> A, vector<int> B){
    n=N;
    for (int i=0;i<n;i++){
        adj[A[i]].pb(B[i]);
        adj[B[i]].pb(A[i]);
    }
    dfs(1, 0);
    hld(1, 1);
    for (int i=1;i<=n;i++){
        if (i==hldpar[i])seg[i]=segtree(num[i]);
    }
}
void update(int u, int x, int y){
    while(u!=0){
        int hd=hldpar[u];
        int bef0, bef1, aft0, aft1;
        seg[hd].calc(bef0, bef1);
        seg[hd].update(pos[u], x, y);
        seg[hd].calc(aft0, aft1);
        x=min(bef0, bef1+1)-min(aft0, aft1+1);
        y=min(bef0+1, bef1)-min(aft0+1, aft1);
        u=par[hd];
    }
}
int query(){
    int x, y;
    seg[1].calc(x, y);
    return min(x, y);
}
int cat(int v){
    st[v]=1;
    update(v, 0, n);
    return query();
}
int dog(int v){
    st[v]=2;
    update(v, n, 0);
    return query();
}
int neighbor(int v){
    if (st[v]==1)update(v, 0, -n);
    else update(v, -n, 0);
    st[v]=0;
    return query();
}

Compilation message (stderr)

catdog.cpp: In function 'void dfs(int, int)':
catdog.cpp:12:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for (int i=0;i<adj[u].size();i++){
      |                  ~^~~~~~~~~~~~~~
catdog.cpp: In function 'void hld(int, int)':
catdog.cpp:23:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int i=0;i<adj[u].size();i++){
      |                  ~^~~~~~~~~~~~~~
catdog.cpp: In function 'void initialize(int, std::vector<int>, std::vector<int>)':
catdog.cpp:46:15: warning: '<anonymous>.segtree::s' may be used uninitialized in this function [-Wmaybe-uninitialized]
   46 |         while(s<n)s*=2;
      |               ^

• Subtask 1: 0 / 8
• Subtask 2: 0 / 30
• Subtask 3: 0 / 62