Submission #33980

#	Time	Username	Problem	Language	Result	Execution time	Memory
33980		mohammad_kilani	Beads and wires (APIO14_beads)	C++14	13 / 100	5 ms	384 KiB

beads

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define oo 2000000000
const int N = 210;
int n , dp[N][2];
vector< pair<int,int> > g[N];

int solve(int node,int prnt,int len,bool b){
	if(dp[node][b] != -1) return dp[node][b];
	int sum = 0 ;
	dp[node][b] = 0 ;
	for(int i=0;i<g[node].size();i++){
		int newnode = g[node][i].first;
		int newlen = g[node][i].second;
		if(newnode != prnt){
			int cur = solve(newnode,node,newlen,0);
			sum+= cur;
		}
	}
	dp[node][b] = sum;
	if(b == 0){
		for(int i=0;i<g[node].size();i++){
			int newnode = g[node][i].first;
			int newlen = g[node][i].second;
			if(newnode == prnt) continue;
			int cur = solve(newnode,node,newlen,0);
			int cur2 = solve(newnode,node,newlen,1);
			dp[node][b] = max(dp[node][b],sum - cur + cur2 + newlen + len);
		}
		for(int i=0;i<g[node].size();i++){
			for(int j=i+1;j<g[node].size();j++){
				int node1 = g[node][i].first;
				int node2 = g[node][j].first;
				int len1 = g[node][i].second;
				int len2 = g[node][j].second;
				if(node1 == prnt || node2 == prnt) continue;
				int cur1 = solve(node1,node,len1,0);
				int cur2 = solve(node1,node,len1,1);
				int cur3 = solve(node2,node,len2,0);
				int cur4 = solve(node2,node,len2,1);
				dp[node][b] = max(dp[node][b],cur4 - cur3 + len1 + cur2 - cur1 + len2 + sum); 
			}
		}
	}
	return dp[node][b];
}

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++){
		memset(dp,-1,sizeof(dp));
		int cur = solve(i,-1,0,1);
		ans = max(ans,solve(i,-1,0,1));
	}
	cout << ans << endl;
	return 0;
}

Compilation message (stderr)

beads.cpp: In function 'int solve(int, int, int, bool)':
beads.cpp:13:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[node].size();i++){
              ~^~~~~~~~~~~~~~~
beads.cpp:23:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<g[node].size();i++){
               ~^~~~~~~~~~~~~~~
beads.cpp:31:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<g[node].size();i++){
               ~^~~~~~~~~~~~~~~
beads.cpp:32:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j=i+1;j<g[node].size();j++){
                  ~^~~~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:61:7: warning: unused variable 'cur' [-Wunused-variable]
   int cur = solve(i,-1,0,1);
       ^~~
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);
   ~~~~~^~~~~~~~~~~~~~~~~~~

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