Submission #119228

#	Time	Username	Problem	Language	Result	Execution time	Memory
119228		patrikpavic2	Roller Coaster Railroad (IOI16_railroad)	C++17	100 / 100	1790 ms	68088 KiB

railroad

#include "railroad.h"
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <map>
#include <unordered_map>
#include <ext/pb_ds/assoc_container.hpp>

#define X first
#define Y second
#define PB push_back

using namespace __gnu_pbds;
using namespace std;

typedef vector < int > vi;
typedef long long ll;
typedef pair < int , int > pii;
typedef vector < pii > vp;

const int INF = 0x3f3f3f3f;
const int N = 4e5 + 500;

bool cmp(pii A, pii B){
	if(A.X - A.Y == B.X - B.Y) return A.X < A.Y;
	return A.X - A.Y > B.X - B.Y;
}

int n, m;
vector < int > v;
vector < pii > e;
gp_hash_table < int , int > deg, par, out;

int pr(int x){
	if(!par[x]) return par[x] = x;
	if(x == par[x]) return x;
	return par[x] = pr(par[x]);
}

void mrg(int x,int y){
	par[pr(x)] = pr(y);
}

ll plan_roller_coaster(vi s, vi t) {
	n = s.size();
	for(int i = 0;i < n;i++){
		deg[s[i]]++; deg[t[i]]--;
		v.PB(s[i]), v.PB(t[i]);
		mrg(s[i], t[i]);
	}
	sort(v.begin(), v.end());
	v.erase(unique(v.begin(), v.end()), v.end());
	n = (int)v.size();
	ll sol = 0;
	for(int i = 0;i < n;i++){
		out[v[i]] = out[v[i - 1]] - deg[v[i]] + (i == 0) - (i == n - 1);
		if(out[v[i]] < 0 && i != n - 1){
			mrg(v[i], v[i + 1]);
			sol -= (ll)(v[i + 1] - v[i]) * out[v[i]];
		}
		if(out[v[i]] == 0 && i != n - 1){
			e.PB({v[i], v[i + 1]});
		}
		if(out[v[i]] > 0 && i != n - 1){
			mrg(v[i], v[i + 1]);
		}
		//printf("OUT %d je %d\n:", v[i], out[v[i]]);
	}
	//printf("SOL	= %lld\n", sol);
	sort(e.begin(), e.end(), cmp);
	for(int i = 0;i < e.size();i++){
		if(pr(e[i].X) != pr(e[i].Y)){
			mrg(e[i].X, e[i].Y);
			sol += e[i].Y - e[i].X;
		}
	}
	return sol;
}	

Compilation message (stderr)

railroad.cpp: In function 'll plan_roller_coaster(vi, vi)':
railroad.cpp:72:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i < e.size();i++){
                ~~^~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 30 / 30
• Subtask 4: 36 / 36