Submission #1055112

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1055112	2024-08-12T14:39:33 Z	Ahmed57	Highway Tolls (IOI18_highway)	C++17	5 / 100	224 ms	262144 KB

highway

#include "bits/stdc++.h"
#include "highway.h"
 
using namespace std;
pair<int,int> p[100001];
int dep[100001];
vector<pair<int,int>> adj[100001];
void dfs(int i,int pr,int id){
    dep[i] = dep[pr]+1;
    p[i] = {pr,id};
    for(auto j:adj[i]){
        if(j.first==pr)continue;
        dfs(j.first,i,j.second);
    }
}
void find_pair(int N, vector<int> U, vector<int> V, int A, int B){
    int m = U.size();
    vector<int> as(m,0);
    vector<int> as2(m,1);
    int len = ask(as);
    int len2 = ask(as2);
    for(int i = 0;i<U.size();i++){
        adj[U[i]].push_back({V[i],i});
        adj[V[i]].push_back({U[i],i});
    }
    dfs(0,0,-1);
    vector<pair<int,int>> v;
    for(int i = 0;i<N;i++){
        v.push_back({dep[i],i});
    }
    sort(v.begin(),v.end());
    reverse(v.begin(),v.end());
    int l = 0 , r = v.size()-2 , ans = 0;
    while(l<=r){
        int mid = (l+r)/2;
        vector<int> as(m,0);
        for(int i = 0;i<=mid;i++){
            as[p[v[i].second].second] = 1;
        }
        if(ask(as)!=len){
            ans = mid;
            r = mid-1;
        }else l = mid+1;
    }
    int a = v[ans].second;
    if(len/A==len2/B){
        int x = len/A;
        int b = a;
        while(x--){
            b = p[b].first;
        }
        answer(a,b);
        return ;
    }
    l = 2 , r = dep[a] ;int ans2 = 0; 
    while(l<=r){
        int mid = (l+r)/2;
        vector<int> as(m,0);
        for(int i = 0;i<N;i++){
            if(dep[i]>=mid){
                as[p[i].second] =1 ;
            }
        }
        int na = ask(as);
        if(na!=(dep[a]-mid+1)*B){
            ans2 = mid;
            l = mid+1;
        }else r = mid-1;
    }
    vector<int> lol;
    l = -1;
    for(int i = 0;i<v.size();i++){
        if(v[i].first==ans2&&l==-1)l = i;
        if(v[i].first==ans2)r = i;
    }   
    int ans3 = 0;
    while(l<=r){
        int mid = (l+r)/2;
        vector<int> as(m,0);
        for(int i = 0;i<=mid;i++){
            as[p[v[i].second].second] = 1;
        }
        if(ask(as)==(dep[a]-ans2+1)*B+B){
            ans3 = mid;
            r = mid-1;
        }else l = mid+1;
    }
    int b = v[ans3].second;
    answer(a,b);
}

Compilation message

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:22:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     for(int i = 0;i<U.size();i++){
      |                   ~^~~~~~~~~
highway.cpp:72:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     for(int i = 0;i<v.size();i++){
      |                   ~^~~~~~~~~

Subtask #1
5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	2648 KB	Output is correct
2	Correct	0 ms	2648 KB	Output is correct
3	Correct	1 ms	2648 KB	Output is correct
4	Correct	1 ms	2648 KB	Output is correct
5	Correct	1 ms	2648 KB	Output is correct
6	Correct	1 ms	2648 KB	Output is correct
7	Correct	1 ms	2648 KB	Output is correct
8	Correct	1 ms	2648 KB	Output is correct
9	Correct	1 ms	2648 KB	Output is correct
10	Correct	1 ms	2648 KB	Output is correct
11	Correct	1 ms	2804 KB	Output is correct
12	Correct	2 ms	2648 KB	Output is correct

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	2648 KB	Output is correct
2	Correct	11 ms	3500 KB	Output is correct
3	Correct	73 ms	10564 KB	Output is correct
4	Correct	82 ms	10400 KB	Output is correct
5	Correct	75 ms	10388 KB	Output is correct
6	Correct	70 ms	10380 KB	Output is correct
7	Correct	68 ms	10496 KB	Output is correct
8	Correct	90 ms	10392 KB	Output is correct
9	Correct	75 ms	10388 KB	Output is correct
10	Correct	70 ms	10384 KB	Output is correct
11	Correct	70 ms	10912 KB	Output is correct
12	Correct	72 ms	11300 KB	Output is correct
13	Correct	85 ms	10932 KB	Output is correct
14	Incorrect	75 ms	10540 KB	Output is incorrect: {s, t} is wrong.
15	Halted	0 ms	0 KB	-

Subtask #3
0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	4136 KB	Output is correct
2	Correct	12 ms	5460 KB	Output is correct
3	Correct	19 ms	6476 KB	Output is correct
4	Correct	55 ms	14072 KB	Output is correct
5	Correct	55 ms	14064 KB	Output is correct
6	Correct	63 ms	13956 KB	Output is correct
7	Correct	58 ms	14264 KB	Output is correct
8	Correct	54 ms	14060 KB	Output is correct
9	Incorrect	56 ms	14080 KB	Output is incorrect: {s, t} is wrong.
10	Halted	0 ms	0 KB	-