Submission #293445

#	Time	Username	Problem	Language	Result	Execution time	Memory
293445		Trickster	Highway Tolls (IOI18_highway)	C++14	0 / 100	20 ms	10620 KiB

highway

#include <algorithm>
#include <highway.h>
#include <string.h>
#include <iostream>
#include <stdio.h>
#include <vector>
#include <queue>
#include <cmath>
#include <set>
#include <map>

using namespace std;

#define maxN 200010
#define ff first
#define ss second
#define ll long long
#define pb push_back
#define mod 1000000007
#define pii pair <ll, ll>
// #pragma GCC target ("avx2")
// #pragma GCC optimization ("O3")
// #pragma GCC optimization ("unroll-loops")
ll bigmod(ll a,ll e) {if(e==0)return 1;ll x=bigmod(a*a%mod,e>>1);return e&1?x*a%mod:x;}

int n, m;
int L[maxN];
vector <pii> Lv[maxN], E[maxN];

void dfs(int nd, int pr, int in)
{
    if(nd) {
        L[nd] = L[pr]+1;
        Lv[L[nd]].pb({nd, in});
    }

    for(auto i: E[nd]) {
        if(i.ff == pr) continue;

        dfs(i.ff, nd, i.ss);
    }
}

void find_pair(int N, vector <int> U, vector <int> V, int A, int B) 
{
    m = U.size();

    for(int i = 0; i < m; i++) {
        E[U[i]].pb({V[i], i});
        E[V[i]].pb({U[i], i});
    }

    // dfs(0, -1, -1);

    vector <int> arr;
    for(int i = 0; i < m; i++) arr.pb(0);

    int ans = ask(arr) / A;

    int l = 0, r = m-1, md, S = 0, T;
    while(l <= r) {
        md = (l+r)/2;

        vector <int> arr;
        for(int i = 0; i < m; i++) arr.pb(0);

        for(int i = 0; i <= md; i++) arr[i] = 1;

        int cur = ask(arr);

        if(ans * A != cur) r = md-1, T = md;
        else l = md+1;
    }

    answer(U[md], V[ans+md]);
}

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:60:29: warning: unused variable 'S' [-Wunused-variable]
   60 |     int l = 0, r = m-1, md, S = 0, T;
      |                             ^
highway.cpp:60:36: warning: variable 'T' set but not used [-Wunused-but-set-variable]
   60 |     int l = 0, r = m-1, md, S = 0, T;
      |                                    ^
highway.cpp:75:16: warning: 'md' may be used uninitialized in this function [-Wmaybe-uninitialized]
   75 |     answer(U[md], V[ans+md]);
      |                ^

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