Submission #105280

#	Time	Username	Problem	Language	Result	Execution time	Memory
105280		ryansee	Robots (APIO13_robots)	C++14	0 / 100	6 ms	2688 KiB

robots

#include "bits/stdc++.h"
using namespace std;
#define FAST ios::sync_with_stdio(false); cin.tie(0);
#define ll long long int
#define ld long double
#define pb push_back
#define ins insert
#define ph push
#define mmst(x,v) memset(x,v,sizeof(x))
#define all(x) (x).begin(), (x).end()
#define FOR(i,s,e) for(ll i=s;i<e;i++)
#define cbr cerr << "hi\n"
#define MAXN (100006)
#define LLINF ((long long)1e18)
typedef pair <ll, ll> pi;
typedef pair <ll, pi> spi;
ll n, A[MAXN], dp[MAXN][102][3], V,ans, alu[MAXN][102][3];
vector<ll>v[MAXN];
// 0 - went down (aka. kid pressed) 
// 1 - ready to go up (aka. pressed)
void up(ll &x, ll y) { x=max(x,y); }
void dfs(ll x, ll p) {
    FOR(i,0,V+1) dp[x][i][0]=dp[x][i][1]=alu[x][i][0]=alu[x][i][1]=-LLINF;
	ll sum = 0; for(auto i:v[x])if(i!=p)sum+=A[i];
	//~ if(p == -1) {
		//~ dp[x][1][1] = sum; if(V>=1)ans = max(ans,sum);
		//~ dp[x][0][1] = 0;
	//~ } else {
		//~ FOR(i,0,V+1) {
			//~ up(dp[x][i][0],dp[p][i][1]);
			//~ up(dp[x][i][1],dp[p][i][0]); // np
			//~ up(dp[x][i][1],dp[p][i][1]);
			//~ if(i>0)up(dp[x][i][1],dp[p][i-1][0]+sum); // press
			//~ if(i>0)up(dp[x][i][1],dp[p][i-1][1]+sum);
//~ // 			up(dp[x][i][2],max({dp[p][i][2],dp[p][i][0]}));
			//~ ans=max({ans,dp[x][i][0],dp[x][i][1]});
		//~ }
	//~ }
	if(v[x].size()==1&&p!=-1) { alu[x][1][1] = dp[x][1][1] = sum; alu[x][0][1] = dp[x][0][1] = 0; ans=max(ans,sum);}
	
	
	for(auto i : v[x]) if(i!=p) {
		dfs(i,x); // sum -= A[i];
		FOR(b,0,V+1) {
			up(dp[x][b][0], dp[i][b][1]);
			up(dp[x][b][1], max(dp[i][b][0],dp[i][b][1]));
			if(b>0)up(dp[x][b][1],max(dp[i][b-1][0],dp[i][b-1][1])+sum);
			//~ ans=max({ans,dp[x][b][0],dp[x][b][1]});
		}
		//~ sum += A[i];
	}
	//~ 0 - went down
	//~ 1 - stayed
	sum += A[p];
	for(auto i : v[x]) if(i!=p) {
		sum -= A[i];
		FOR(b,0,V+1) {
			up(alu[x][b][0],alu[i][b][1]);
			up(alu[x][b][1],max(alu[i][b][0],alu[i][b][1]));
			if(b>0)up(alu[x][b][1],max(alu[i][b-1][0],alu[i][b-1][1])+sum);
			ans=max({ans,alu[x][b][0],alu[x][b][1]});
		}
		sum += A[i];
	}
	return;
}

int main()
{
	// freopen("in","r",stdin);
	FAST
	cin>>n>>V; if(n==1) { cout << 0 << '\n'; return 0; }
	FOR(i,1,n+1)cin>>A[i]; for(ll i=0;i<n-1;i++) { ll a, b; cin >> a >> b; v[a].pb(b); v[b].pb(a); }
// 	ll ans = 0;
	FOR(i,1,n+1) {
	    if((i>1&&n>1000))break;
// 		for(ll i=0;i<MAXN;i++) for(ll j=0;j<102;j++) dp[i][j][0]=dp[i][j][1]=dp[i][j][2]=-LLINF;
		dfs(i,-1);
	// ll ans = 0;
// 		for(ll i=1;i<=n;i++) for(ll j=0;j<=V;j++)ans=max({ans,dp[i][j][0],dp[i][j][1],dp[i][j][2]}); 
	}
	//~ dfs(6,-1);
	cout<<ans<<'\n';
}
/*
 * 
12 2
2 3 3 8 1 5 6 7 8 3 5 4
2 1
2 7
3 4
4 7
7 6
5 6
6 8
6 9
7 10
10 11
10 12
* 
*/

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:11:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
 #define FOR(i,s,e) for(ll i=s;i<e;i++)
                    ^
robots.cpp:73:2: note: in expansion of macro 'FOR'
  FOR(i,1,n+1)cin>>A[i]; for(ll i=0;i<n-1;i++) { ll a, b; cin >> a >> b; v[a].pb(b); v[b].pb(a); }
  ^~~
robots.cpp:73:25: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  FOR(i,1,n+1)cin>>A[i]; for(ll i=0;i<n-1;i++) { ll a, b; cin >> a >> b; v[a].pb(b); v[b].pb(a); }
                         ^~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 40