Submission #911535

#	Time	Username	Problem	Language	Result	Execution time	Memory
911535		biank	Mechanical Doll (IOI18_doll)	C++17	100 / 100	172 ms	22168 KiB

doll

#include <bits/stdc++.h>
#include "doll.h"
using namespace std;
#define SIZE(x) (int)x.size()
#define forn(i,n) for(int i=0;i<int(n);i++)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define pb push_back
typedef vector<int> vi;
         
vi L, R, v, state;
int t=1, skip, s=-1;
     
void build(int u, int l, int r) {
    L.pb(0), R.pb(0), v.pb(0);
    assert(u>=0 && u<SIZE(v));
    if(r<=l) {
        v[u]=-1;
        return;
    }
    if(skip>0 && r-l<=skip) {
        v[u]=-1;
        skip-=r-l;
        return;
    }
    if(r-l==1) return;
    v[u] = s--;
    int m=(l+r)/2;
    L[u] = t++;
    build(L[u], l, m);
    R[u] = t++;
    build(R[u], m, r);
}
     
bool dfs(int u, int a) {
    assert(u>=0 && u<SIZE(v));
    if(u!=0 && v[u]==-1) return false;
    if(!v[u]) {
        v[u]=a;
        return true;
    }
    state[u]^=1;
    assert(v[L[u]]!=-1 || v[R[u]]!=-1);
    if(state[u]) return dfs(L[u],a);
    return dfs(R[u],a);
}

bool first_subtasks(int m, vi a) {
    vi c(m+1),x,y;
    
    map<int,vi> next;
    int n=SIZE(a);
    a.pb(0);
    forn(i,n) next[a[i]].pb(a[i+1]);
    
    c[0]=a[0];
    int j=0;
    for(auto &p:next) {
        auto [a,v] = p;
        int S=SIZE(v);
        if(S==1) {
            c[a] = v[0];
        } else if(S==2) {
            c[a] = --j;
            x.pb(v[0]);
            y.pb(v[1]);
            continue;
        } else if(S==4) {
            c[a] = --j;
            x.pb(--j);
            y.pb(--j);
            x.pb(v[0]);
            y.pb(v[2]);
            x.pb(v[1]);
            y.pb(v[3]);
            continue;
        } else if(S==3) {
            c[a] = --j;
            x.pb(--j);
            y.pb(--j);
            x.pb(v[0]);
            y.pb(v[1]);
            x.pb(j+2);
            y.pb(v[2]);
        } else {
            return false;
        }
    }
    answer(c,x,y);
    return true;
}
     
void create_circuit(int m, vi A) {
    if(first_subtasks(m,A)) return;
    vi c(m+1);
    c[0]=A[0];
    forsn(i,1,m+1) c[i]=-1;
    int n=SIZE(A), sz=1;
    while(sz<n) sz*=2;
    assert(sz>=n);
    skip = sz-n;
    build(0,0,sz);
    assert(SIZE(L)==SIZE(R) && SIZE(v)==SIZE(L));
    vi a;
    forsn(i,1,n) a.pb(A[i]);
    a.pb(0);
    state.assign(SIZE(v),0);
    forn(i,n) {
        bool flag=0;
        while(!flag) flag=dfs(0,a[i]);
    }
    vi x, y;
    int mini=-1;
    forn(i,SIZE(v)) {
        if(L[i] && R[i]) {
            x.pb(v[L[i]]);
            y.pb(v[R[i]]);
            mini=min({mini,v[L[i]],v[R[i]]});
        }
    }
    if(SIZE(x)<-mini) {
        x.resize(-mini,-1);
        y.resize(-mini,-1);
    }
    answer(c,x,y);
}

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 18 / 18
• Subtask 6: 56 / 56