Submission #1105612

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105612		cpptowin	Hotspot (NOI17_hotspot)	C++17	38 / 100	10 ms	848 KiB

hotspot

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 6010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e6
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
#define UNIQUE(v) v.erase(unique(all(v)),v.end())
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if(x < 0) x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if(x < 0) x += mod;
}
int n,m;
vi ke[N];
int d[2][N],f[2][N];
double sum[N];
void dij(int inp,int d[],int f[],int n)
{
    fo(i,0,n - 1) d[i] = inf,f[i] = 1;
    d[inp] = 0;
    f[inp] = 1;
    priority_queue<pii,vii,greater<pii>> q;
    q.push({0,inp});
    while(q.size())
    {
        auto [du,u] = q.top();
        q.pop();
        if(d[u] != du) continue;
        for(int v : ke[u])
        {
            if(minimize(d[v],du + 1))
            {
                f[v] = f[u];
                q.push({d[v],v});
            }
            else if(f[v] == du + 1) f[v] += f[u];
        }
    }
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m;
    fo(i,1,m) 
    {
        int u,v;
        cin >> u >> v;
        ke[u].pb(v);
        ke[v].pb(u);
    }
    int q;cin >> q;
    while(q--)
    {
        int u,v;
        cin >> u >> v;
        dij(u,d[0],f[0],n);
        dij(v,d[1],f[1],n);
        fo(i,0,n - 1) if(d[0][i] + d[1][i] == d[0][v])
        {
            sum[i] += (double)(f[0][i] * f[1][i] / f[0][v]);
        }
    }
    double res = 0;
    int ans = 0;
    fo(i,0,n - 1) if(maximize(res,sum[i])) ans = i;
    cout << ans;
}

Compilation message (stderr)

hotspot.cpp:85:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   85 | main()
      | ^~~~
hotspot.cpp: In function 'int main()':
hotspot.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
hotspot.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 18 / 18
• Subtask 5: 0 / 26
• Subtask 6: 0 / 36