Submission #566776

#	Time	Username	Problem	Language	Result	Execution time	Memory
566776		shrimb	Saveit (IOI10_saveit)	C++17	75 / 100	220 ms	14016 KiB

encoder

#include<bits/stdc++.h>
#include "grader.h"
#include "encoder.h"

using namespace std;




void encode(int n, int h, int p, int a[], int b[]){

    vector<int>adj[n];


    int dis[n],par[n];
    for(int i = 0; i < n; i++) {
        dis[i] = 1000000000;
    }
    for(int i = 0; i < p; i++){
        adj[a[i]].push_back(b[i]);
        adj[b[i]].push_back(a[i]);
    }
    memset(par, -1, sizeof par);
    dis[0] = par[0] = 0;
    vector<int>d = {0};
    int j = 0;
    while(j < d.size()){
        for(auto s: adj[d[j]]){
            if(dis[s] == 1000000000){
                dis[s] = dis[d[j]] + 1;
                par[s] = d[j];
                d.push_back(s);
            }
        }
        j++;
    }

    for(int i = 1; i < n; i++){
        // if (par[i] == -1) assert(0);
        for(int k = 0; k < 10; k++){
            if(par[i] & (1 << k)) encode_bit(1);
            else encode_bit(0);
        }
    }
    for(int i = 1; i < h; i++){
        vector<int>pc(n, 1000000000);
        pc[i] = 0;
        int j = 0;
        vector<int>b = {i};
        while(j < b.size()){
            for(auto s:adj[b[j]]){
                if(pc[s] == 1000000000){
                    pc[s] = pc[b[j]] + 1;
                    b.push_back(s);
                }
            }
            j++;
        }
        for(int k = 1; k < n; k++){
            int diff = pc[k] - pc[par[k]];
            if(diff != 0){
                encode_bit(1);
                if(diff < 0) encode_bit(1);
                else encode_bit(0);
            }else{
                encode_bit(0);
            }
        }
    }


}

decoder

#include<bits/stdc++.h>
#include "grader.h"
#include "decoder.h"

using namespace std;


void decode(int n, int h){
    int dis[n],p[n],j;
    vector<int> diff[n];
    vector<int>adj[n];


    j = 0;
    for(int i = 0; i < n; i++) {
        diff[i].resize(n);
        dis[i] = 1000000000;
    }
    for(int i = 0; i < n; i++){
        for(int k = 0; k < n; k++) diff[i][k] = 0;
    }
    for(int i = 1; i < n; i++){
        int parent = 0;
        for(int k = 0; k < 10; k++){
            if(decode_bit()) parent += (1 << k);
        }
        p[i] = parent;
        adj[i].push_back(parent);
        adj[parent].push_back(i);
    }
    dis[0] = j = 0;
    vector<int>b = {0};
    while(j < b.size()){
        // cerr << j << endl;
        for(auto s: adj[b[j]]){
            if(dis[s] == 1000000000){
                dis[s] = dis[b[j]] + 1;
                b.push_back(s);
            }
        }
        j++;
    }
    for(int i = 0; i < n; i++) {
        if (dis[i] == 1000000000) assert(0);
        hops(0,i, dis[i]);
    }


    for(int i = 1; i < h; i++){
        for(int k = 1; k < n; k++){
            if(!decode_bit()){
                diff[k][p[k]] = diff[p[k]][k] = 0;
            }else{
                if(decode_bit()){
                    diff[k][p[k]] = 1;
                    diff[p[k]][k] = -1;
                }else{
                    diff[p[k]][k] = 1;
                    diff[k][p[k]] = -1;
                }
            }
        }
        vector<int>pc(n, 1000000000);
        pc[i] = j = 0;
        vector<int>bb = {i};
        while(j < bb.size()){
            for(auto s:adj[bb[j]]){
                if(pc[s] == 1000000000){
                    pc[s] = pc[bb[j]] + diff[bb[j]][s];
                    bb.push_back(s);
                }
            }
            j++;
        }
        for(int t = 0; t < n; t++){
            // if (pc[t] == 1000000000) cerr << t <<  endl;
            hops(i,t,pc[t]);
        }
    }

}

Compilation message (stderr)

encoder.cpp: In function 'void encode(int, int, int, int*, int*)':
encoder.cpp:27:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     while(j < d.size()){
      |           ~~^~~~~~~~~~
encoder.cpp:50:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |         while(j < b.size()){
      |               ~~^~~~~~~~~~

decoder.cpp: In function 'void decode(int, int)':
decoder.cpp:33:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     while(j < b.size()){
      |           ~~^~~~~~~~~~
decoder.cpp:66:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |         while(j < bb.size()){
      |               ~~^~~~~~~~~~~

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