oj.uz

답안 #35068

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
35068 2017-11-17T22:07:28 Z model_code Mousetrap (CEOI17_mousetrap) C++11
100 / 100
 1483 ms 162088 KB 
#include <iostream>
#include <iomanip>
#include <climits>
#include <stack>
#include <fstream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <deque>
#include <queue>
#include <set>
#include <map>
#include <cassert>

#define FOR(i,n) for(int i=0,_n=n;i<_n;i++)
#define FORR(i,s,n) for(int i=s,_n=n;i<_n;i++)
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define pli pair<ll,int>
#define vi vector<int>
#define fs first
#define sec second

#define maxn 1000000

using namespace std;
typedef long long ll;

const ll MOD = 1000000007LL;

vi drevo[maxn+5];
int parent[maxn+5];
int cena[maxn+5];
vector <pii> subtrees;
int ispath[maxn+5];
int root, mis, n;

int dfs1(int poz, int pr){//dobi podatke o starsu, vrne podatek o tem, ali se nahaja na poti do misi oz. kako dalec je
	int stars=-1;
	FOR(i,drevo[poz].size())if(drevo[poz][i]==pr)stars=i;
	if(stars!=-1)drevo[poz].erase(drevo[poz].begin()+stars);
	parent[poz]=pr;
	int napoti=-1;
	if(poz==mis)napoti=0;
	FOR(i,drevo[poz].size())napoti=max(napoti,dfs1(drevo[poz][i],poz));
	ispath[poz]=napoti;
	if(napoti==-1)return napoti;
	return napoti+1;
}

void dfs2(int poz, int c){//izracuna ceno sebe in sinov in po potrebi doda v subtrees
	if(drevo[poz].size()==0){//list
		cena[poz]=c;
		return;
	}
	if(ispath[poz]==-1){
		int nyuc=c+drevo[poz].size();
		FOR(i,drevo[poz].size())dfs2(drevo[poz][i],nyuc);
		if(drevo[poz].size()==1){
			cena[poz]=c+1;
			return;
		}
		int best=-1;
		int sbest=-1;
		FOR(i,drevo[poz].size()){
			if(cena[drevo[poz][i]]>best){
				sbest=best;
				best=cena[drevo[poz][i]];
				continue;
			}
			if(cena[drevo[poz][i]]>sbest)sbest=cena[drevo[poz][i]];
		}
		cena[poz]=sbest;
		return;
	}
	int nyuc=c+drevo[poz].size()-1;//ne stejemo povezave naprej po poti
	if(poz==root)nyuc=0;
	if(poz==mis)nyuc++;//ce smo pri misi, potem ni nadaljevanja poti
	FOR(i,drevo[poz].size())dfs2(drevo[poz][i],nyuc);
	if(poz==root)return;//v korenu nam ni treba nic vec rezat
	FOR(i,drevo[poz].size())if(ispath[drevo[poz][i]]==-1)subtrees.pb(mp(ispath[poz],cena[drevo[poz][i]]));
}

int main(){
	scanf("%d%d%d",&n,&root,&mis);
	root--;
	mis--;
	FOR(i,n-1){
		int a,b;
		scanf("%d%d",&a,&b);
		a--,b--;
		drevo[a].pb(b);
		drevo[b].pb(a);
	}
	int pathl = dfs1(root,-1);
	dfs2(root,0);
	sort(subtrees.begin(),subtrees.end());
	int l=0,d=n;
	while(l<d){
		int s=(l+d)/2;
		int x=0,y=0,pt=0;
		FOR(i,pathl){
			if(pt>=subtrees.size()){
				d=s;
				break;
			}
			x++;
			int ydelta=0;
			while(pt<subtrees.size() && subtrees[pt].fs<=i){
				if(subtrees[pt].sec+y>s){//rezat treba
					ydelta++;
					x--;
				}
				pt++;
			}
			y+=ydelta;
			if(x<0 || y>s){//ni bilo dovolj rezov
				l=s+1;
				break;
			}
		}
	}
	printf("%d\n",l);
	return 0;
}

Compilation message

mousetrap.cpp: In function 'int main()':
mousetrap.cpp:107:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(pt>=subtrees.size()){
         ^
mousetrap.cpp:113:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(pt<subtrees.size() && subtrees[pt].fs<=i){
            ^
mousetrap.cpp:89:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&n,&root,&mis);
                               ^
mousetrap.cpp:94:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&a,&b);
                      ^

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 37176 KB Output is correct
2 Correct 9 ms 37176 KB Output is correct
3 Correct 13 ms 37176 KB Output is correct
4 Correct 13 ms 37176 KB Output is correct
5 Correct 3 ms 37176 KB Output is correct
6 Correct 6 ms 37176 KB Output is correct
7 Correct 6 ms 37176 KB Output is correct
8 Correct 6 ms 37176 KB Output is correct
9 Correct 6 ms 37176 KB Output is correct
10 Correct 9 ms 37176 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 433 ms 68460 KB Output is correct
2 Correct 479 ms 65292 KB Output is correct
3 Correct 1483 ms 69516 KB Output is correct
4 Correct 576 ms 53412 KB Output is correct
5 Correct 1453 ms 69516 KB Output is correct
6 Correct 1426 ms 69516 KB Output is correct

Subtask #3
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 37176 KB Output is correct
2 Correct 9 ms 37176 KB Output is correct
3 Correct 13 ms 37176 KB Output is correct
4 Correct 13 ms 37176 KB Output is correct
5 Correct 3 ms 37176 KB Output is correct
6 Correct 6 ms 37176 KB Output is correct
7 Correct 6 ms 37176 KB Output is correct
8 Correct 6 ms 37176 KB Output is correct
9 Correct 6 ms 37176 KB Output is correct
10 Correct 9 ms 37176 KB Output is correct
11 Correct 3 ms 37176 KB Output is correct
12 Correct 6 ms 37176 KB Output is correct
13 Correct 0 ms 37176 KB Output is correct
14 Correct 9 ms 37176 KB Output is correct
15 Correct 13 ms 37176 KB Output is correct
16 Correct 6 ms 37176 KB Output is correct
17 Correct 3 ms 37176 KB Output is correct
18 Correct 6 ms 37176 KB Output is correct
19 Correct 0 ms 37176 KB Output is correct
20 Correct 6 ms 37176 KB Output is correct
21 Correct 3 ms 37176 KB Output is correct
22 Correct 3 ms 37176 KB Output is correct

Subtask #4
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 37176 KB Output is correct
2 Correct 9 ms 37176 KB Output is correct
3 Correct 13 ms 37176 KB Output is correct
4 Correct 13 ms 37176 KB Output is correct
5 Correct 3 ms 37176 KB Output is correct
6 Correct 6 ms 37176 KB Output is correct
7 Correct 6 ms 37176 KB Output is correct
8 Correct 6 ms 37176 KB Output is correct
9 Correct 6 ms 37176 KB Output is correct
10 Correct 9 ms 37176 KB Output is correct
11 Correct 433 ms 68460 KB Output is correct
12 Correct 479 ms 65292 KB Output is correct
13 Correct 1483 ms 69516 KB Output is correct
14 Correct 576 ms 53412 KB Output is correct
15 Correct 1453 ms 69516 KB Output is correct
16 Correct 1426 ms 69516 KB Output is correct
17 Correct 3 ms 37176 KB Output is correct
18 Correct 6 ms 37176 KB Output is correct
19 Correct 0 ms 37176 KB Output is correct
20 Correct 9 ms 37176 KB Output is correct
21 Correct 13 ms 37176 KB Output is correct
22 Correct 6 ms 37176 KB Output is correct
23 Correct 3 ms 37176 KB Output is correct
24 Correct 6 ms 37176 KB Output is correct
25 Correct 0 ms 37176 KB Output is correct
26 Correct 6 ms 37176 KB Output is correct
27 Correct 3 ms 37176 KB Output is correct
28 Correct 3 ms 37176 KB Output is correct
29 Correct 6 ms 37176 KB Output is correct
30 Correct 436 ms 68460 KB Output is correct
31 Correct 463 ms 68460 KB Output is correct
32 Correct 426 ms 162084 KB Output is correct
33 Correct 439 ms 162088 KB Output is correct
34 Correct 1453 ms 69516 KB Output is correct
35 Correct 1423 ms 69516 KB Output is correct
36 Correct 1413 ms 81840 KB Output is correct
37 Correct 1483 ms 81840 KB Output is correct
38 Correct 1146 ms 82992 KB Output is correct
39 Correct 1239 ms 82996 KB Output is correct
40 Correct 1176 ms 82992 KB Output is correct