Submission #566647

#	Time	Username	Problem	Language	Result	Execution time	Memory
566647		RealSnake	Saveit (IOI10_saveit)	C++14	50 / 100	228 ms	16304 KiB

encoder

#include "bits/stdc++.h"
using namespace std;
#include "grader.h"
#include "encoder.h"

void encode(int n, int h, int p, int a[], int b[]) {
    vector<int> v[n];
    for(int i = 0; i < p; i++) {
        v[a[i]].push_back(b[i]);
        v[b[i]].push_back(a[i]);
    }
    set<int> s;
    s.insert(0);
    int par[n] = {};
    par[0] = 1;
    vector<int> v2[n];
    while(s.size()) {
        int x = *s.begin();
        s.erase(s.begin());
        for(int i : v[x]) {
            if(!par[i]) {
                v2[x].push_back(i);
                v2[i].push_back(x);
                par[i] = x + 1;
                s.insert(i);
            }
        }
    }
    for(int i = 0; i < n; i++)
        sort(v2[i].begin(), v2[i].end());
    for(int i = 1; i < n; i++) {
        int x = par[i] - 1;
        for(int j = 0; j < 10; j++)
            encode_bit(((x & (1 << j)) > 0));
    }
    int ans[n][h];
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < h; j++)
            ans[i][j] = 1e9;
    }
    set<pair<int, pair<int, int>>> ss;
    for(int i = 0; i < h; i++) {
        ss.insert({0, {i, i}});
        ans[i][i] = 0;
    }
    while(ss.size()) {
        pair<int, pair<int, int>> p = *ss.begin();
        ss.erase(ss.begin());
        int x = p.second.first, hub = p.second.second;
        int cost = p.first;
        if(cost > ans[x][hub])
            continue;
        for(int i : v[x]) {
            if(cost + 1 < ans[i][hub]) {
                ans[i][hub] = cost + 1;
                ss.insert({cost + 1, {i, hub}});
            }
        }
    }
    bool vis[n];
    for(int i = 0; i < h; i++) {
        for(int j = 0; j < n; j++)
            vis[j] = 0;
        s.insert(i);
        vis[i] = 1;
        while(s.size()) {
            int x = *s.begin();
            s.erase(s.begin());
            for(int j : v2[x]) {
                if(vis[j])
                    continue;
                vis[j] = 1;
                s.insert(j);
                if(j <= i)
                    continue;
                int dif = ans[j][i] - ans[x][i];
                if(dif == 0)
                    encode_bit(0);
                else {
                    encode_bit(1);
                    if(dif == 1)
                        encode_bit(1);
                    else
                        encode_bit(0);
                }
            }
        }
    }
}

decoder

#include "bits/stdc++.h"
using namespace std;
#include "grader.h"
#include "decoder.h"

void decode(int n, int h) {
    vector<int> v[n];
    for(int i = 1; i < n; i++) {
        int x = 0;
        for(int j = 0; j < 10; j++) {
            if(decode_bit())
                x += (1 << j);
        }
        v[x].push_back(i);
        v[i].push_back(x);
    }
    for(int i = 0; i < n; i++)
        sort(v[i].begin(), v[i].end());
    int ans[n][n];
    bool vis[n];
    for(int i = 0; i < h; i++) {
        for(int j = 0; j < n; j++)
            vis[j] = 0;
        ans[i][i] = 0;
        set<int> s;
        s.insert(i);
        vis[i] = 1;
        while(s.size()) {
            int x = *s.begin();
            s.erase(s.begin());
            if(x >= i) {
                hops(i, x, ans[x][i]);
                if(x < h && x != i)
                    hops(x, i, ans[x][i]);
            }
            for(int j : v[x]) {
                if(vis[j])
                    continue;
                vis[j] = 1;
                s.insert(j);
                if(j <= i)
                    continue;
                int dif = decode_bit();
                if(dif) {
                    if(!decode_bit())
                        dif = -1;
                }
                ans[j][i] = ans[i][j] = ans[x][i] + dif;
            }
        }
    }
}

• Subtask 1: 25 / 25
• Subtask 2: 25 / 25
• Subtask 3: 0 / 25
• Subtask 4: 0 / 25