oj.uz

답안 #122331

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
122331 2019-06-28T05:03:20 Z 임유진(#2991) 구슬과 끈 (APIO14_beads) C++14
0 / 100
 6 ms 5120 KB 
#include<stdio.h>
#include<vector>

using namespace std;

#define MAXN 200005

typedef long long lint;
typedef pair<lint, lint> pll;

const lint LINF=1ll<<50;
vector<pll> e[MAXN];
pll par[MAXN];
lint D[MAXN], P[MAXN];

void dfs(lint x){
	lint psum=0ll;
	lint mx[2]={-LINF, -LINF};
	for(auto a:e[x]) if(a.second!=par[x].second){
		par[a.second]=make_pair(a.first, x);
		dfs(a.second);
		psum+=P[a.second];
		lint t=D[a.second]-P[a.second]+a.first;
		mx[1]=max(t, mx[1]);
		if(mx[1]>mx[0]) swap(mx[0], mx[1]);
	}
	D[x]=psum+max(0ll, mx[0]+mx[1]);
	P[x]=max(D[x], psum+mx[0]+par[x].first);
}

int main(){
	lint N;
	lint a[MAXN], b[MAXN], c[MAXN];

	scanf("%lld", &N);
	for(lint i=0; i<N-1; i++) scanf("%lld%lld%lld", a+i, b+i, c+i);

	for(lint i=0; i<N-1; i++){
		e[a[i]].push_back(make_pair(c[i], b[i]));
		e[b[i]].push_back(make_pair(c[i], a[i]));
	}
	par[1]=make_pair(0ll, 0ll);
	dfs(1ll);
	printf("%lld", D[1]);
	return 0;
}

Compilation message

beads.cpp: In function 'int main()':
beads.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld", &N);
  ~~~~~^~~~~~~~~~~~
beads.cpp:36:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(lint i=0; i<N-1; i++) scanf("%lld%lld%lld", a+i, b+i, c+i);
                            ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Incorrect 6 ms 5120 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Incorrect 6 ms 5120 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Incorrect 6 ms 5120 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Incorrect 6 ms 5120 KB Output isn't correct
7 Halted 0 ms 0 KB -