Submission #1106612

#	Time	Username	Problem	Language	Result	Execution time	Memory
1106612		Ahmed57	Sphinx's Riddle (IOI24_sphinx)	C++17	28.50 / 100	200 ms	1992 KiB

sphinx

#include <bits/stdc++.h>
#include "sphinx.h"
 
using namespace std;
int pr[251];
vector<int> adjj[251];
int find(int x){
    if(x==pr[x])return x;
    return pr[x] = find(pr[x]);
}
bool mergegroup(int a,int b){
    a = find(a);
    b = find(b);
    if(a==b)return 0;
    pr[a] = b;
    return 1;
}
vector<int> find_colours(int n,vector<int> X,vector<int> Y){
    for(int i = 0;i<X.size();i++){
        adjj[X[i]].push_back(Y[i]);
        adjj[Y[i]].push_back(X[i]);
    }
    stack<int> q;
    set<int> s;
    for(int i = 0;i<n;i++){
        s.insert(i);
    }
    vector<int> col(n,0);
    int d = 0;
    while(!s.empty()){
        q.push((*s.begin()));
        while(!q.empty()){
            int i = q.top();
            q.pop();
            if(s.find(i)==s.end())continue;
            s.erase(i);
        vector<int> v;
        for(auto j:adjj[i]){
            if(s.find(j)==s.end()){
                v.push_back(j);
            }
        }
        int sz = v.size();
        int l = 0 , r = sz-1, ans = -1;
        while(l<=r){
            int mid = (l+r)/2;
            vector<int> e(n,n);
            e[i] = -1;
            for(int j = 0;j<=mid;j++){
                e[v[j]] = -1;
            }
            int cnt = 0;
            for(int j = 0;j<n;j++){
                pr[j] = j;cnt++;
            }
            for(int j = 0;j<X.size();j++){
                if(e[X[j]]==-1&&e[Y[j]]==-1){
                    if(X[j]==i||Y[j]==i)continue;
                    if(col[X[j]]==col[Y[j]])cnt-=mergegroup(X[j],Y[j]);
                }else if(e[X[j]]==n&&e[Y[j]]==n){
                    cnt-=mergegroup(X[j],Y[j]);
                }
            }
            if(cnt==perform_experiment(e)){
                l = mid+1;
            }else {
                ans = mid;
                r = mid-1;
            }
        }
        if(ans==-1){
            col[i] = d++;
        }else{
            col[i] = col[v[ans]];
        }
        for(auto j:adjj[i]){
            if(s.find(j)!=s.end()){
                q.push(j);
            }
        }
        }
    }
    return col;
}

Compilation message (stderr)

sphinx.cpp: In function 'std::vector<int> find_colours(int, std::vector<int>, std::vector<int>)':
sphinx.cpp:19:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for(int i = 0;i<X.size();i++){
      |                   ~^~~~~~~~~
sphinx.cpp:56:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |             for(int j = 0;j<X.size();j++){
      |                           ~^~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 1.5 / 3
• Subtask 2: 0 / 7
• Subtask 3: 16.5 / 33
• Subtask 4: 10.5 / 21
• Subtask 5: 0 / 36