Submission #341470

#	Time	Username	Problem	Language	Result	Execution time	Memory
341470		ryansee	Power Plant (JOI20_power)	C++14	100 / 100	199 ms	28460 KiB

power

#include "bits/stdc++.h"
using namespace std;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 

long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (200006)
ll n, dp[MAXN][2], ans;
vector<int> v[MAXN];
string A;
void dfs(int x,int p) {
	for(auto i:v[x]) if(i^p) dfs(i, x);
	for(auto i:v[x]) if(i^p) dp[x][0] += dp[i][0];
	if(A[x-1] == '1') {
		for(auto i:v[x]) if(i^p) dp[x][1] += max(dp[i][0], dp[i][1]);
		-- dp[x][1];
		for(auto i:v[x]) if(i^p) ans = max(ans, dp[x][0] - dp[i][0] + dp[i][1] + 1);
		dp[x][1] = max(dp[x][1], dp[x][0] + 1);
	} else {
		for(auto i:v[x]) if(i^p) dp[x][1] += max(dp[i][0], dp[i][1]);
	}
}
int main() {
	FAST
	cin>>n;
	FOR(i,2,n){
		ll a,b;
		cin>>a>>b;
		v[a].eb(b), v[b].eb(a);
	}
	cin>>A;
	dfs(1, 1);
	cout<<max({dp[1][0], dp[1][1], dp[1][2], ans})<<'\n';
}

Compilation message (stderr)

power.cpp: In function 'int main()':
power.cpp:54:40: warning: array subscript 2 is above array bounds of 'll [2]' {aka 'long long int [2]'} [-Warray-bounds]
   54 |  cout<<max({dp[1][0], dp[1][1], dp[1][2], ans})<<'\n';
      |                                 ~~~~~~~^

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