Submission #116961

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
116961	2019-06-14T09:00:23 Z	pzdba	Highway Tolls (IOI18_highway)	C++14	6 / 100	182 ms	24600 KB

highway

#include <bits/stdc++.h>
#include "highway.h"
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
vector<pii> g[90005];
int depth[90005], par[90005];
vector<int> ud[90005];

void dfs(int u, int p, int j, int d){
    depth[u] = d;
    par[u] = j;
    ud[d].push_back(u);
    for(int i=0;i<g[u].size();i++){
        int v = g[u][i].first, j = g[u][i].second;
        if(v == p) continue;
        dfs(v, u, j, d+1);
    }
}
void find_pair(int n, std::vector<int> u, std::vector<int> v, int a, int b){
    int m = u.size();
    for(int i=0;i<m;i++){
        int a = u[i], b = v[i];
        g[a].push_back(pii(b, i));
        g[b].push_back(pii(a, i));
    }
    dfs(0, -1, 0, 0);
    vector<int> w;
    w.resize(m);
    LL base = ask(w);
    int lo = 1, hi = n, dd = 0, s = 0, t = 0;
    while(lo <= hi){
        int mid = (lo+hi)/2;
        for(int i=0;i<m;i++) w[i] = 0;
        for(int j=mid;j<=n;j++){
            for(int k=0;k<ud[j].size();j++){
                int u = ud[j][k];
                w[par[u]] = 1;
            }
        }
        LL tmp = ask(w);
        if(tmp > base) lo = mid+1, dd = mid;
        else hi = mid-1;
    }
    lo = 0, hi = ud[dd].size()-1;
    while(lo <= hi){
        int mid = (lo+hi)/2;
        for(int i=0;i<m;i++) w[i] = 0;
        for(int j=0;j<=mid;j++){
            int u = ud[dd][j];
            w[par[u]] = 1;
        }
        LL tmp = ask(w);
        if(tmp > base) hi = mid-1, s = ud[dd][mid];
        else lo = mid+1;
    }
    for(int i=0;i<=n;i++) ud[i].clear();
    dfs(s, -1, 0, 0);
    dd = base/a;
    lo = 0, hi = ud[dd].size()-1;
    while(lo <= hi){
        int mid = (lo+hi)/2;
        for(int i=0;i<m;i++) w[i] = 0;
        for(int j=0;j<=mid;j++){
            int u = ud[dd][j];
            w[par[u]] = 1;
        }
        LL tmp = ask(w);
        if(tmp > base) hi = mid-1, t = ud[dd][mid];
        else lo = mid+1;
    }
    answer(s, t);
}

Compilation message

highway.cpp: In function 'void dfs(int, int, int, int)':
highway.cpp:14:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<g[u].size();i++){
                 ~^~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:36:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(int k=0;k<ud[j].size();j++){
                         ~^~~~~~~~~~~~~

Subtask #1
0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	6 ms	4520 KB	Output is incorrect: {s, t} is wrong.
2	Halted	0 ms	0 KB	-

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	6 ms	4600 KB	Output is incorrect: {s, t} is wrong.
2	Halted	0 ms	0 KB	-

Subtask #3
6.0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	24 ms	5876 KB	Output is correct
2	Correct	41 ms	7260 KB	Output is correct
3	Correct	63 ms	8564 KB	Output is correct
4	Correct	159 ms	16908 KB	Output is correct
5	Correct	165 ms	16884 KB	Output is correct
6	Correct	166 ms	16956 KB	Output is correct
7	Correct	182 ms	16792 KB	Output is correct
8	Correct	177 ms	16968 KB	Output is correct
9	Correct	156 ms	16892 KB	Output is correct