Submission #565345

#	Time	Username	Problem	Language	Result	Execution time	Memory
565345		shrimb	Saveit (IOI10_saveit)	C++17	75 / 100	201 ms	14012 KiB

encoder

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


void encode(int n, int h, int p, int *v1, int *v2){
    vector<int> adj[n];
    for (int i = 0 ; i < p ; i++) {
        adj[v1[i]].push_back(v2[i]);
        adj[v2[i]].push_back(v1[i]);
    }

    int par[n];
    {
        queue<int> q;
        vector<bool> vis(n);
        q.push(0);
        while (q.size()) {
            auto cur = q.front();
            q.pop();
            for (int j : adj[cur]) {
                if (!vis[j]) {
                    vis[j] = 1;
                    par[j] = cur;
                    q.push(j);
                }
            }
        }
    }
    auto sendnum = [&](int x) {
        for (int k = 0 ; k < 10 ; k++) {
            encode_bit(!!(x & (1 << k)));
        }
    };
    for (int i = 1 ; i < n ; i++) sendnum(par[i]);
    for (int i = 1 ; i < h ; i++) {
        queue<int> q;
        vector<int> dis(n, -1);
        dis[i] = 0;
        q.push(i);
        while (q.size()) {
            auto cur = q.front();
            q.pop();
            for (int j : adj[cur]) {
                if (dis[j] == -1) {
                    dis[j] = dis[cur] + 1;
                    q.push(j);
                }
            }
        }
        for (int i = 1 ; i < n ; i++) {
            int x = dis[i] - dis[par[i]];
            if (x == 1) encode_bit(1), encode_bit(1);
            else if (x == -1) encode_bit(0);
            else encode_bit(1), encode_bit(0);
        }
    }
}

decoder

#include "grader.h"
#include "decoder.h"
#include "bits/stdc++.h"
using namespace std;
void decode(int n, int h) {
    vector<int> adj[n];
    int par[n];
    auto getnum = [&]() {
        int ret = 0;
        for (int k = 0 ; k < 10 ; k++) {
            ret |= (1 << k)*decode_bit();
        }
        return ret;
    };
    for (int i = 1 ; i < n ; i++) {
        int x = getnum();
        par[i] = x;
        adj[i].push_back(x);
        adj[x].push_back(i);
    }
    {
        queue<int> q;
        vector<int> dis(n, -1);
        dis[0] = 0;
        q.push(0);
        while (q.size()) {
            auto cur = q.front();
            q.pop();
            for (int j : adj[cur]) {
                if (dis[j] == -1) {
                    dis[j] = dis[cur] + 1;
                    q.push(j);
                }
            }
        }
        for (int i = 0 ; i < n ; i++) {
            hops(0, i, dis[i]);
        }
    }
    int w[n][n];
    for (int i = 1 ; i < h ; i++) {
        for (int j = 1 ; j < n ; j++) {
            int v;
            if (decode_bit()) {
                if (decode_bit()) v = 1;
                else v = 0;
            } else {
                v = -1;
            }
            w[par[j]][j] = v;
            w[j][par[j]] = -v;
        }
        queue<int> q;
        vector<int> dis(n, -1e9);
        dis[i] = 0;
        q.push(i);
        while (q.size()) {
            auto cur = q.front();
            q.pop();
            for (int j : adj[cur]) {
                if (dis[j] == -1e9) {
                    dis[j] = dis[cur] + w[cur][j];
                    q.push(j);
                }
            }
        }
        for (int j = 0 ; j < n ; j++) {
            hops(i, j, dis[j]);
        }
    }
}

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