Submission #1055128

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1055128	2024-08-12T14:43:04 Z	Ahmed57	Highway Tolls (IOI18_highway)	C++17	18 / 100	190 ms	262144 KB

highway

#include "bits/stdc++.h"
#include "highway.h"
 
using namespace std;
#define int long long
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(int32_t N, vector<int32_t> U, vector<int32_t> V, int32_t A, int32_t B){
    int m = U.size();
    vector<int32_t> as(m,0);
    vector<int32_t> 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<int32_t> 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<int32_t> 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<int32_t> 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(int32_t, std::vector<int>, std::vector<int>, int32_t, int32_t)':
highway.cpp:23:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for(int i = 0;i<U.size();i++){
      |                   ~^~~~~~~~~
highway.cpp:73:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |     for(int i = 0;i<v.size();i++){
      |                   ~^~~~~~~~~

Subtask #1
5.0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4696 KB	Output is correct
2	Correct	1 ms	4696 KB	Output is correct
3	Correct	1 ms	4696 KB	Output is correct
4	Correct	1 ms	4696 KB	Output is correct
5	Correct	1 ms	4696 KB	Output is correct
6	Correct	1 ms	4696 KB	Output is correct
7	Correct	1 ms	4696 KB	Output is correct
8	Correct	1 ms	4696 KB	Output is correct
9	Correct	1 ms	4696 KB	Output is correct
10	Correct	1 ms	4704 KB	Output is correct
11	Correct	1 ms	4696 KB	Output is correct
12	Correct	1 ms	4696 KB	Output is correct

Subtask #2
7.0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	4696 KB	Output is correct
2	Correct	9 ms	5816 KB	Output is correct
3	Correct	74 ms	13744 KB	Output is correct
4	Correct	71 ms	13744 KB	Output is correct
5	Correct	80 ms	13744 KB	Output is correct
6	Correct	85 ms	13712 KB	Output is correct
7	Correct	64 ms	13744 KB	Output is correct
8	Correct	70 ms	13808 KB	Output is correct
9	Correct	69 ms	13744 KB	Output is correct
10	Correct	80 ms	13748 KB	Output is correct
11	Correct	85 ms	14820 KB	Output is correct
12	Correct	86 ms	15280 KB	Output is correct
13	Correct	72 ms	14992 KB	Output is correct
14	Correct	70 ms	14480 KB	Output is correct

Subtask #3
6.0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	6232 KB	Output is correct
2	Correct	12 ms	7632 KB	Output is correct
3	Correct	21 ms	8644 KB	Output is correct
4	Correct	61 ms	17584 KB	Output is correct
5	Correct	63 ms	17584 KB	Output is correct
6	Correct	57 ms	17584 KB	Output is correct
7	Correct	56 ms	17584 KB	Output is correct
8	Correct	66 ms	17532 KB	Output is correct
9	Correct	56 ms	17584 KB	Output is correct