oj.uz

Submission #1028093

# Submission time Handle Problem Language Result Execution time Memory
1028093 2024-07-19T13:25:23 Z Dan4Life Towns (IOI15_towns) C++17
25 / 100
 15 ms 1280 KB 
#include "towns.h"
#include <bits/stdc++.h>
using namespace std;
#define sz(a) (int)a.size()
using ar2 = array<int,2>;
const int mxN = 115;
int n, mem[mxN][mxN];
map<int,int> M;
 
int dis(int a, int b){
	if(a==b) return 0;
	if(mem[a][b]!=-1) return mem[a][b];
	if(mem[b][a]!=-1) return mem[b][a];
	return mem[a][b]=mem[b][a]=getDistance(a,b);
}
 
int p[mxN], sz[mxN];
int findSet(int i) { return p[i]==i?i:p[i]=findSet(p[i]); }
bool isSameSet(int i, int j) { return findSet(i)==findSet(j); }
 
void unionSet(int i, int j){
	int x = findSet(i), y = findSet(j);
	if(x==y) return;
	if(sz[x]<sz[y]) swap(x,y);
	p[y]=x; sz[x]+=sz[y];
}

int a, b, diameter; 
bool same(int i, int j){
	int branch = (dis(a,i)+dis(b,i)-diameter)/2;
	int lpos = dis(a,i)-branch;
	int rpos = diameter-lpos;
	int i_u = dis(a,i)-lpos;
	if(dis(a,i)<dis(b,i)) i_u = dis(b,i)-rpos;
	int u_j = dis(a,j)-lpos;
	if(dis(a,j)<dis(b,j)) u_j = dis(b,j)-rpos;
	return i_u+u_j != dis(i,j);
}

int hubDistance(int N, int sub) {
	n = N; ar2 mx = {0,0};
	a = 0, b = 0; M.clear();
	memset(mem,-1,sizeof(mem));
	for(int i = 0; i < n; i++) 
		mx=max(mx,{dis(0,i),i});
	a = mx[1]; mx = {0,0};
	for(int i = 0; i < n; i++)
		mx=max(mx,{dis(a,i),i});
	b = mx[1]; diameter = mx[0];
	int ans = diameter;
 
	for(int i = 0; i < n; i++){
		if(i==a or i==b) continue;
		int branch = (dis(a,i)+dis(b,i)-diameter)/2;
		int lpos = dis(a,i)-branch;
		int rpos = diameter-lpos;
		M[lpos]=max({M[lpos],branch,lpos,rpos});
	}
	for(auto u : M) ans=min(ans,u.second);
	if(sub<=2) return ans;
	
	for(auto u : M){
		int lpos = u.first, mx_dis = u.second;
		if(mx_dis!=ans) continue;
		
		for(int i = 0; i < n; i++) p[i]=i, sz[i]=1;
		for(int i = 0; i < n; i++){
			if(i!=a and i!=b) continue;
			for(int j = 0; j < n; j++)
				if(same(i,j)) unionSet(i,j);
		}
		if(sub==4){
			if(sz[findSet(a)]>n/2) return -ans;
			if(sz[findSet(b)]>n/2) return -ans;
			int tot = sz[findSet(a)]+sz[findSet(b)];
			int left = n-tot;
			if(left>n/2) return -ans;
			return ans;
		}
		stack<int> S = stack<int>();
		for(int i = 0; i < n; i++){
			if(sz(S) > n-i) return ans;
			if(!sz(S) or same(S.top(),i)) S.push(i);
			else S.pop();
		}
		if(sz(S)) return ans;
	}
	return -ans;
}

Compilation message

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:63:7: warning: unused variable 'lpos' [-Wunused-variable]
   63 |   int lpos = u.first, mx_dis = u.second;
      |       ^~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 1116 KB Output is correct
2 Correct 12 ms 900 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 10 ms 1068 KB Output is correct
5 Correct 11 ms 860 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 1112 KB Output is correct
2 Correct 8 ms 880 KB Output is correct
3 Correct 10 ms 860 KB Output is correct
4 Correct 10 ms 1036 KB Output is correct

Subtask #3
0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 860 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 15 ms 1280 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 12 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 39.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -