제출 #36906

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
36906		mohammad_kilani	구슬과 끈 (APIO14_beads)	C++14	28 / 100	1082 ms	5504 KiB

beads

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define oo 2000000000
const int N = 200010;
vector< pair<int,int> > g[N];
int n , dp[N][2] , q[N], in[N];
pair<int,int> v[N];

int calc(int node){
	int st = 0 , en = 0 , curnode , w , sum = 0;
	for(int i=1;i<=n;i++){
		in[i] = g[i].size() - (i != node);
		if(in[i] == 0)
			q[en++] = i;
	}
	while(st < en){
		curnode = q[st++];
		dp[curnode][1] = dp[curnode][0] = 0;
		sum = 0 ;
		for(int i=0;i<g[curnode].size();i++){
			if(in[g[curnode][i].first] != 0){
				w = g[curnode][i].second;
				in[g[curnode][i].first]--;
				if(in[g[curnode][i].first] == 0){
					q[en++] = g[curnode][i].first;
				}
				v[i] = make_pair(-1,-1);
			}
			else{
				v[i] = make_pair(dp[g[curnode][i].first][0],dp[g[curnode][i].first][1]);
				sum += max(v[i].first,v[i].second);
			}
		}
		dp[curnode][1] = sum;
		for(int i=0;i<g[curnode].size();i++){
			if(v[i].first == -1) continue;
			sum -= max(v[i].first,v[i].second);
			sum += w + g[curnode][i].second + v[i].second;
			dp[curnode][0] = max(dp[curnode][0],sum);
			sum += max(v[i].first,v[i].second);
			sum -= (w + g[curnode][i].second + v[i].second);
		}

	}
	return dp[node][1];
}

int main() {
	//freopen("in.txt","r",stdin);
	scanf("%d",&n);
	for(int i=0;i<n-1;i++){
		int u ,v , w;
		scanf("%d%d%d",&u,&v,&w);
		g[u].push_back(make_pair(v,w));
		g[v].push_back(make_pair(u,w));
	}
	int ans = 0 ;
	for(int i=1;i<=n;i++){
		if(g[i].size() == 1){
			ans = max(ans,calc(i));
		}
	}
	printf("%d\n",ans);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

beads.cpp: In function 'int calc(int)':
beads.cpp:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<g[curnode].size();i++){
               ~^~~~~~~~~~~~~~~~~~
beads.cpp:36:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<g[curnode].size();i++){
               ~^~~~~~~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:51:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
beads.cpp:54:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d",&u,&v,&w);
   ~~~~~^~~~~~~~~~~~~~~~~~~
beads.cpp: In function 'int calc(int)':
beads.cpp:42:14: warning: 'w' may be used uninitialized in this function [-Wmaybe-uninitialized]
    sum -= (w + g[curnode][i].second + v[i].second);
            ~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 15 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43