Submission #862778

#	Time	Username	Problem	Language	Result	Execution time	Memory
862778		nnhzzz	Power Plant (JOI20_power)	C++14	100 / 100	75 ms	29952 KiB

power

// cre: Nguyen Ngoc Hung - Train VOI 2024

#include<bits/stdc++.h>

using namespace std;

#define        __nnhzzz__  signed main()
#define          BIT(i,j)  ((i>>j)&1LL)
#define           MASK(i)  (1LL<<i)
#define            ALL(x)  (x).begin(),(x).end()
#define             SZ(x)  (int)(x).size()
#define               gcd  __gcd
#define                fi  first
#define                se  second
#define                ll  long long
#define               ull  unsigned long long
#define                ld  long double
#define                vi  vector<int>
#define               vvi  vector<vi>
#define              vvvi  vector<vvi>
#define               pii  pair<int,int>
#define              vpii  vector<pii>
#define        REP(i,a,b)  for(int i = (a); i<=(b); ++i)
#define       REPD(i,a,b)  for(int i = (a); i>=(b); --i)
#define   REPDIS(i,a,b,c)  for(int i = (a); i<=(b); i+=c)

//-------------------------------------------------------------//
const int oo = 1e9,LOG = 20,MAXN = 2e5+7,N = 1e2+3;
const int MOD = 1e9+7,MOD1 = 1e9+207,MOD2 = 1e9+407,MOD3 = 998244353;
//-------------------------------------------------------------//
template<typename T> bool mini(T &a, const T &b){if(a>b){a=b;return true;}return false;}
template<typename T> bool maxi(T &a, const T &b){if(a<b){a=b;return true;}return false;}

/*
----------------------------------------------------------------
    END OF TEMPLATE
----------------------------------------------------------------
    Nguyen Ngoc Hung - nnhzzz
    Training for VOI24 gold medal
----------------------------------------------------------------
*/

int dp[MAXN],x[MAXN];
vi adj[MAXN];
int res = 0;

int dfs(int u, int par){
    int ma = 0;
    for(auto &v:adj[u]){
        if(v==par) continue;
        dp[u] += dfs(v,u);
        maxi(ma,dp[v]);
    }
    dp[u] = max(dp[u]-x[u],x[u]);
    maxi(res,max(dp[u],ma+x[u]));
    return dp[u];
}

void solve(){
    int n; cin >> n;
    REP(i,2,n){
        int u,v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    string s; cin >> s;
    REP(i,1,n) x[i] = s[i-1]-'0';
    dfs(1,0);
    cout << res;
}

__nnhzzz__{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    #define name "test"
    if(fopen(name".inp","r")){
        freopen(name".inp","r",stdin);
        freopen(name".out","w",stdout);
    }
    #define name1 "nnhzzz"
    if(fopen(name1".inp","r")){
        freopen(name1".inp","r",stdin);
        freopen(name1".out","w",stdout);
    }
    int test = 1;
    while(test--){
        solve();
    }
    cerr << "\nTime elapsed: " << 1000*clock()/CLOCKS_PER_SEC << "ms\n";
    return 0;
}

Compilation message (stderr)

power.cpp: In function 'int main()':
power.cpp:77:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |         freopen(name".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
power.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |         freopen(name".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
power.cpp:82:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |         freopen(name1".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
power.cpp:83:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen(name1".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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