Submission #431036

#	Time	Username	Problem	Language	Result	Execution time	Memory
431036		juggernaut	Regions (IOI09_regions)	C++17	85 / 100	8061 ms	30144 KiB

regions

#include<bits/stdc++.h>
#define fr first
#define sc second
using namespace std;
void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
typedef long long ll;
#define USING_ORDERED_SET 0
#if USING_ORDERED_SET
#include<bits/extc++.h>
using namespace __gnu_pbds;
template<class T>using ordered_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#endif
template<class T>void umax(T &a,T b){if(a<b)a=b;}
template<class T>void umin(T &a,T b){if(b<a)a=b;}
#ifdef IOI2021SG
    #define printl(args...)printf(args)
#else
    #define printl(args...)((void)0)
#endif
int n,r,q;
int reg[200005];
vector<int>g[200005];
int timer;
int tin[200005];
int tout[200005];
int precalc[5005][5005];
bool big[25005];
int id[25005];
int tot;
int cnt[25005];
int tmp[25005];
void dfs(int v){
    if(big[reg[v]])for(int i=1;i<=tot;i++)precalc[i][id[reg[v]]]+=tmp[i];
    tmp[id[reg[v]]]++;
    tin[v]=++timer;
    for(int to:g[v])dfs(to);
    tout[v]=++timer;
    tmp[id[reg[v]]]--;
}
vector<pair<int,int>>color[25005];
vector<int>spec[25005];
int main(){
    scanf("%d%d%d",&n,&r,&q);
    scanf("%d",&reg[1]);
    cnt[reg[1]]++;
    for(int i=2;i<=n;i++){
        int par;
        cnt[reg[i]]++;
        scanf("%d%d",&par,&reg[i]);
        g[par].push_back(i);
    }
    for(int i=1;i<=r;i++)if(cnt[i]>20){
        big[i]=true;
        id[i]=++tot;
    }
    if(tot>5000)exit(-1);
    dfs(1);
    for(int i=1;i<=n;i++){
        spec[reg[i]].push_back(tout[i]);
        color[reg[i]].emplace_back(tin[i],tout[i]);
    }
    for(int i=1;i<=r;i++){
        sort(color[i].begin(),color[i].end());
        sort(spec[i].begin(),spec[i].end());
    }
    while(q--){
        int x,y;
        scanf("%d%d",&x,&y);
        int ans=0;
        if(big[x]&&big[y]){
            ans=precalc[id[x]][id[y]];
        }else if(color[x].size()<color[y].size()){
            for(auto to:color[x]){
                ans+=(lower_bound(color[y].begin(),color[y].end(),make_pair(to.sc,0))-color[y].begin())-(lower_bound(color[y].begin(),color[y].end(),make_pair(to.fr,0))-color[y].begin());
            }
        }else{
            for(auto to:color[y]){
                ans+=(lower_bound(color[x].begin(),color[x].end(),make_pair(to.fr,0))-color[x].begin());
                ans-=lower_bound(spec[x].begin(),spec[x].end(),to.fr)-spec[x].begin();
            }
        }
        printf("%d\n",ans);
        fflush(stdout);
    }
}

Compilation message (stderr)

regions.cpp: In function 'void usaco(std::string)':
regions.cpp:5:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:5:66: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                                                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp: In function 'int main()':
regions.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     scanf("%d%d%d",&n,&r,&q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
regions.cpp:44:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |     scanf("%d",&reg[1]);
      |     ~~~~~^~~~~~~~~~~~~~
regions.cpp:49:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |         scanf("%d%d",&par,&reg[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:68:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |         scanf("%d%d",&x,&y);
      |         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 70 / 85