Submission #1074651

#	Time	Username	Problem	Language	Result	Execution time	Memory
1074651		wood	Highway Tolls (IOI18_highway)	C++17	12 / 100	75 ms	9252 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> p32;
typedef pair<ll,ll> p64;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define vi vector<int>
#define vp32 vector<p32>
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define MOD %1000000007
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using Tree =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//never guess
//never debug without reviewing code
//never try adding ones or substracting them
//only step by step debug when necessay


void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
    int n = N, m = U.size();
    vp32 adj[n];
    int vertex[m];
    for(int i = 0; i<m; i++){
        adj[U[i]].eb(V[i],i);
        adj[V[i]].eb(U[i],i);
    }
    queue<p32> q;
    q.emplace(0,-1);
    p32 depth[n]; memset(depth,0,sizeof depth); depth[0] = p32(1,-1);
    while(!q.empty()){
        p32 x = q.front();
        q.pop();
        for(p32 ii : adj[x.fi]){
            if(!depth[ii.fi].fi){
                depth[ii.fi].fi = depth[x.fi].fi+1;
                depth[ii.fi].se = ii.se;
                q.push(ii);
                vertex[ii.se] = ii.fi;
            }
        }
    }
    vi w(m);
    ll d = ask(w)/A;
    vector<int> v;
    for(int i = 0; i<n ;i++){
        if(depth[i].fi==d+1) v.pb(depth[i].se);
    }
    int l = -1, r = v.size()-1;
    while(r-l>1){
        int mid = (r+l)/2;
        vi soel(m);
        for(int i = l+1; i<=mid; i++){
            soel[v[i]] = 1;
        }
        if(ask(soel)==d*A) l = mid;
        else r = mid;
    }
    answer(0,vertex[v[r]]);
}

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:37:46: warning: 'void* memset(void*, int, size_t)' clearing an object of type 'p32' {aka 'struct std::pair<int, int>'} with no trivial copy-assignment; use assignment instead [-Wclass-memaccess]
   37 |     p32 depth[n]; memset(depth,0,sizeof depth); depth[0] = p32(1,-1);
      |                                              ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:64,
                 from /usr/include/c++/10/vector:60,
                 from highway.h:3,
                 from highway.cpp:1:
/usr/include/c++/10/bits/stl_pair.h:211:12: note: 'p32' {aka 'struct std::pair<int, int>'} declared here
  211 |     struct pair
      |            ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31