oj.uz

Submission #715151

# Submission time Handle Problem Language Result Execution time Memory
715151 2023-03-26T03:12:05 Z vjudge1 Towns (IOI15_towns) C++17
100 / 100
 16 ms 884 KB 
#include "towns.h"
#include <bits/stdc++.h>
using namespace std;
 
int hubDistance(int n, int sub) {
	vector<int> d0(n), d1(n);
	int mx = 0, R = 1e9;
	for (int i = 1; i < n; ++i) {
		d0[i] = getDistance(0, i);
		if (d0[i] > d0[mx]) mx = i;
	}
	d1[0] = d0[mx];
	int d = d0[mx];
	map<int, vector<int>> groups;
	for (int i = 1; i < n; ++i) if (i != mx) {
		d1[i] = getDistance(mx, i);
		groups[(d1[i] - d0[i] + d0[mx]) / 2].push_back(i);
		d = max(d, d1[i]);
	}
	int hub = 0, lft = 1, rht = n-1;
	for (auto g: groups) {
		R = min(R, max(g.first, d-g.first));
	}
	// cerr << mx << endl;
	for (auto g: groups) {
		rht -= g.second.size();
		if (max(g.first, d-g.first) == R) {
			if (lft <= n/2 && rht <= n/2) {
				int mst = -1, cnt=0, qcnt=0;
				vector<int> head(n), sz(n);
				auto same_st = [&](int a, int b) {qcnt++;return a == b || getDistance(a, b) != d1[a]+d1[b] - 2*g.first;};
				for (int i = 0; i < g.second.size(); ++i) {
					if (!cnt) mst = g.second[i];
					if (same_st(mst, g.second[i])) {
						cnt++;
						head[g.second[i]] = mst;
						sz[mst]++;
					} else {
						cnt--;
						head[g.second[i]] = g.second[i];
						sz[g.second[i]] = 1;
					}
				}
				bool ignore = 0;
				for (int i = g.second.size(); i--;) if (g.second[i] != mst) {
					if (head[g.second[i]] == g.second[i]) {
						if (same_st(mst, g.second[i])) {
							sz[mst]+=sz[g.second[i]];
						}
					}
				}
				if (sz[mst] > n/2) return -R;
				return R;
			}
		}
		lft += g.second.size();
	}
	return -R;
}

Compilation message

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:26:24: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   26 |   rht -= g.second.size();
      |                        ^
towns.cpp:32:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for (int i = 0; i < g.second.size(); ++i) {
      |                     ~~^~~~~~~~~~~~~~~~~
towns.cpp:45:31: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   45 |     for (int i = g.second.size(); i--;) if (g.second[i] != mst) {
      |                  ~~~~~~~~~~~~~^~
towns.cpp:44:10: warning: unused variable 'ignore' [-Wunused-variable]
   44 |     bool ignore = 0;
      |          ^~~~~~
towns.cpp:56:24: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   56 |   lft += g.second.size();
      |                        ^
towns.cpp:20:6: warning: unused variable 'hub' [-Wunused-variable]
   20 |  int hub = 0, lft = 1, rht = n-1;
      |      ^~~
towns.cpp:5:28: warning: unused parameter 'sub' [-Wunused-parameter]
    5 | int hubDistance(int n, int sub) {
      |                        ~~~~^~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 852 KB Output is correct
2 Correct 11 ms 748 KB Output is correct
3 Correct 1 ms 300 KB Output is correct
4 Correct 14 ms 852 KB Output is correct
5 Correct 15 ms 824 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 400 KB Output is correct
2 Correct 13 ms 724 KB Output is correct
3 Correct 13 ms 820 KB Output is correct
4 Correct 16 ms 852 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 816 KB Output is correct
2 Correct 15 ms 852 KB Output is correct
3 Correct 1 ms 300 KB Output is correct
4 Correct 14 ms 852 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 728 KB Output is correct

Subtask #5
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 448 KB Output is correct
2 Correct 14 ms 824 KB Output is correct
3 Correct 15 ms 844 KB Output is correct

Subtask #6
39.0 / 39.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 340 KB Output is correct
2 Correct 14 ms 844 KB Output is correct
3 Correct 13 ms 884 KB Output is correct