Submission #293364

#	Time	Username	Problem	Language	Result	Execution time	Memory
293364		Gajowy	Power Plant (JOI20_power)	C++14	100 / 100	258 ms	28856 KiB

power

#pragma GCC optimize("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define mp make_pair
#define eb emplace_back
#define pb push_back
#define e1 first
#define e2 second
#define int int_fast32_t
#define uint uint_fast64_t
#define ll int_fast64_t
#define ull uint_fast64_t
#define int16 int_fast16_t
#define uint16 uint_fast16_t
#define int32 int_fast32_t
#define uint32 uint_fast32_t
#define int64 int_fast64_t
#define uint64 uint_fast64_t
#define ld long double
#define float long double
#define size(x) (int)x.size()
#define satori int testCases; cin>>testCases; while(testCases--)
#define fastio ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define all(r) begin(r),end(r)
#define rall(r) rbegin(r),rend(r)
#define time chrono::high_resolution_clock().now().time_since_epoch().count()
#define elapsed(__begin,__end) (__end-__begin)/CLOCKS_PER_SEC
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
float pi=3.14159265358979323846;

const int MAXN=2e5+10;

int dp[MAXN],dp2[MAXN],pp[MAXN],pr[MAXN];
vector<int> g[MAXN];
string s;

void dfs(int u,int p)
{
	pr[u]=p;
	dp[u]=pp[u];
	int sm=-pp[u];
	for(auto v:g[u])
		if(v!=p)
			dfs(v,u),sm+=dp[v];
	dp[u]=max(dp[u],sm);
}

void dfs2(int u,int p)
{
	int sm=dp2[u];
	for(auto v:g[u])
		if(v!=p)
			sm+=dp[v];
	for(auto v:g[u])
		if(v!=p)
			dp2[v]=max(pp[u],sm-dp[v]-pp[u]),dfs2(v,u);
}

int32_t main()
{
	fastio;
	int n,u,v,res=0;
	cin>>n;
	for(int i=1;i<n;i++)
		cin>>u>>v,g[u].eb(v),g[v].eb(u);
	cin>>s;
	for(int i=0;i<n;i++)
		pp[i+1]=(int)(s[i]-'0');
	dfs(1,0);
	dfs2(1,0);
	for(int i=1;i<=n;i++)
	{
		res=max(res,dp[i]+dp2[i]);
		for(auto vv:g[i])
			if(vv!=pr[i])
				res=max(res,pp[i]+dp[vv]);
	}
	cout<<res<<'\n';
}

Compilation message (stderr)

power.cpp:2: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    2 | #pragma GCC optimization ("O3")
      | 
power.cpp:3: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    3 | #pragma GCC optimization ("unroll-loops")
      |

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53