oj.uz

Submission #714880

# Submission time Handle Problem Language Result Execution time Memory
714880 2023-03-25T11:36:41 Z lam Towns (IOI15_towns) C++14
100 / 100
 15 ms 1100 KB 
#include "towns.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
#define ff first
#define ss second
const int maxn = 510;
int n;
int d[maxn][maxn];
int ds[maxn],up[maxn];
map<ii,int> cnt;
int Ask(int u, int v)
{
    if (u==v) return 0;
    if (u>v) swap(u,v);
    if (d[u][v] == -1)
    {
        d[u][v] = getDistance(u,v);
//        cerr<<u<<" - "<<v<<" = "<<d[u][v]<<endl;
    }
    return d[u][v];
}
bool check(int dist)
{
    vector<int> to_mid(n+1,0);
    for (int i=0; i<n; i++)
        if (ds[i]<dist) to_mid[i]=dist-ds[i]+up[i];
    else to_mid[i]=ds[i]-dist+up[i];
    vector <int> sz(n+1,0);
    int alive = 0; int num=1;
    for (int i=1; i<n; i++)
        if (num==0)
    {
        num=1;
        sz[i]++; alive=i;
    }
    else
    {
        if (Ask(i,alive)==to_mid[i]+to_mid[alive])
        {
            num--; sz[i]++;
        }
        else
        {
            num++;
            sz[alive]++;
        }
    }
    if (num<=0) return 1;
    num=0;
    for (int i=0; i<n; i++) if (sz[i]!=0)
    {
        if (Ask(i,alive)==to_mid[i]+to_mid[alive]) num-=sz[i];
        else num+=sz[i];
    }
    return num<=0;
}

int hubDistance(int N, int sub) {
    n=N;
    cnt.clear();
    for (int i=0; i<n; i++)
        for (int j=0; j<n; j++) d[i][j] = -1;
    int u,v,dist; dist=0;
    u=0;
    for (int i=1; i<n; i++) if (dist<Ask(0,i))
    {
        u=i;
        dist=Ask(0,i);
    }
    v=0; dist=Ask(0,u);
    for (int i=1; i<n; i++) if (dist<Ask(u,i))
    {
        dist=Ask(u,i);
        v=i;
    }
    int R=1e9;
    for (int i=0; i<n; i++)
    {
        int x=Ask(u,i); int y=Ask(i,0);
        int z=Ask(u,0);
        up[i] = (x+y-z)/2;
        ds[i] = x-up[i];
//        cout<<x<<' '<<y<<' '<<z<<'\n';
//        cout<<i<<" := "<<up[i]<<' '<<ds[i]<<'\n';
        R=min(R,max(ds[i],dist-ds[i]));
        cnt[{ds[i],dist-ds[i]}]++;
    }
    int sum = 0;
    int it = 0;
    int dau = -1;
    for (auto i:cnt)
    {
        int sz = i.ss;
        if (max(i.ff.ff,i.ff.ss)==R)
        {
            if (sz<=n/2&&sum<=n/2&&(n-sz-sum)<=n/2)
            {
                dau=1;
                it=0;
                break;
            }
            else if (sum<=n/2&&(n-sz-sum)<=n/2)
            {
                it=i.ff.ff;
            }
        }
        sum+=sz;
    }
    if (it!=0)
    {
        if (check(it)) dau=1;
        else dau=-1;
    }
    return dau*R;

}

Compilation message

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:65:11: warning: variable 'v' set but not used [-Wunused-but-set-variable]
   65 |     int u,v,dist; dist=0;
      |           ^
towns.cpp:60:28: warning: unused parameter 'sub' [-Wunused-parameter]
   60 | int hubDistance(int N, int sub) {
      |                        ~~~~^~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 468 KB Output is correct
2 Correct 13 ms 468 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 13 ms 556 KB Output is correct
5 Correct 12 ms 552 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 468 KB Output is correct
2 Correct 10 ms 468 KB Output is correct
3 Correct 12 ms 556 KB Output is correct
4 Correct 12 ms 468 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 556 KB Output is correct
2 Correct 14 ms 1052 KB Output is correct
3 Correct 1 ms 304 KB Output is correct
4 Correct 13 ms 1048 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 484 KB Output is correct

Subtask #5
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 468 KB Output is correct
2 Correct 13 ms 548 KB Output is correct
3 Correct 15 ms 1100 KB Output is correct

Subtask #6
39.0 / 39.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 556 KB Output is correct
2 Correct 13 ms 1056 KB Output is correct
3 Correct 13 ms 1096 KB Output is correct