Submission #1120410

#	Time	Username	Problem	Language	Result	Execution time	Memory
1120410		vjudge1	KOVANICE (COI15_kovanice)	C++17	50 / 100	119 ms	19868 KiB

kovanice

// Ali
 
// #pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long int
#define ins insert      
#define pii pair<int,int>
#define pb push_back
#define endl '\n'
#define putr(x) cout<<x<<endl;return; 
#define all(x) x.begin(),x.end()
const int mod = 1e9 +7, sze = 3e5+23, inf = 2e9, LG = 19,pr = 31;
int val[sze];

struct lan{
    vector<int> parent;
    vector<int> sz;
    lan(int n){
        parent.resize(n+23);
        iota(all(parent),0);
        sz.resize(n+23,1);
    }

    int root(int a){
        if(parent[a]==a){
            return a;
        }
        return parent[a]=root(parent[a]);
    }
    void unite(int a,int b){
        int x = root(a);
        int y = root(b);
        if(x!=y){
            if(sz[x]<sz[y]){
                swap(x,y);
            }
            sz[x]+=sz[y];
            parent[y]=x;
        }
    }
};
void fast(){
    int n,m,qq;
    cin>>n>>m>>qq;
    vector<pair<pii,char>> q;
    bool flag=false;
    while(qq--){
        string s;
        cin>>s;
        string a="";
        string b="";
        char op;
        for(auto v:s){
            if(v=='<' || v=='='){
                op = v;
                swap(a,b);
            }   
            else{
                a+=v;
            }
        }
        swap(a,b);
        q.pb({{stoll(a),stoll(b)},op});
        // cout<<a<<" "<<op<<" "<<b<<endl;
        if(op=='<' && !flag){
            flag=true;
        }
    }
    lan dsu(m+23);
    if(flag){
        vector<int> fk(m+23,0);
        for(auto [vv,op]:q){
            int a = vv.first;
            int b = vv.second;
            if(op=='='){
                dsu.unite(a,b);
            }
            else{
                val[a]=1;
                val[b]=2;
            }
        }
        for(int i =1;i<=m;i++){
            // cout<<i<<" "<<dsu.root(i)<<" "<<val[i]<<endl;
            fk[dsu.root(i)]|=val[i];
        }
        for(int i =1;i<=m;i++){
            val[i]=fk[dsu.root(i)];
        }
    }

    for(int i=1;i<=m;i++){
        if(val[i]<=0){
            cout<<"?"<<endl;
        }
        else{
            cout<<"K"<<val[i]<<endl;
        }
    }
}
  
 
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    int tt = 1;
    // cin>>tt;
 
    while(tt--){
        fast();
    }
    return 0;
}

Compilation message (stderr)

kovanice.cpp: In function 'void fast()':
kovanice.cpp:66:9: warning: 'op' may be used uninitialized in this function [-Wmaybe-uninitialized]
   66 |         if(op=='<' && !flag){
      |         ^~

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40