Submission #1042682

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042682		kukuk	Power Plant (JOI20_power)	C++14	100 / 100	96 ms	29588 KiB

power

#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
typedef long long ll;
typedef unsigned long long int ull;
const ll md = 1e9+7;
const int ukr = 2e5+10;
int read() {
    int ketek = 0; bool ne=0;
    register char c = getchar();
    while(c == ' ' or c =='\n') c =getchar();
    if(c=='-'){ne = 1; c = getchar();}
    while(c >= '0' and c <='9') { ketek = (ketek<<3)+(ketek<<1)+c-'0'; c = getchar();}
    if(ne) ketek*=-1;
    return ketek;
}   
void print(int x) {
    if (x < 0) {putchar('-');x = -x;}
    int len = 0, buf[10];
    if (x == 0) {putchar('0');return;}
    while (x > 0) {buf[len++] = x % 10; x/=10;}
    while (len > 0) {putchar('0' + buf[--len]);}
}
void File_Work(){
	freopen("test.in","r",stdin);
	freopen("test.out","w",stdout);
}
int n, m, a, b, c, d, id;
struct babi{
    ll x, y, id;
};
struct babis{
    ll x, y;
};
ll gcd(ll a, ll b) {
   if (b == 0) return a;
   return gcd(b, a % b);
}
ll pgkt(ll rnx, ll rny){
    if(rny == 0) return 1;
    ll nwrn = pgkt(rnx, rny/2);
    if(rny%2){
        return (((nwrn*nwrn)%md)*rnx)%md;
    }else{
        return (nwrn*nwrn)%md;
    }
}
vector<vector<int>> adj(ukr);
string s;
ll dp[ukr] = {0}, ans = 0;
void rec(ll rn, ll par){
    if(s[rn-1] == '1') dp[rn] = 1;
    else dp[rn] = 0;
    ll tot = 0, ck = (s[rn-1]-'0');
    for(auto i : adj[rn]){
        if(i == par) continue;
        rec(i, rn);
        tot += dp[i];
        ans = max(ans, dp[i]+ck);
    }
    dp[rn] = max(dp[rn], tot-ck);
    //cout << dp[rn] << " " << rn << "\n";
    ans = max(ans, dp[rn]);
}
void solve(){
    cin >> n;
    for(int i = 0; i < n-1; i++){
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    cin >> s;
    rec(1, 1);
    cout << ans;
}
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	int t =1;
    //cin >> t;
    for(int i = 1; i <= t; i++){
        //cout << "Case " << i << ": ";
        solve();
    }
}

Compilation message (stderr)

power.cpp: In function 'void File_Work()':
power.cpp:25:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |  freopen("test.in","r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
power.cpp:26:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |  freopen("test.out","w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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