Submission #914565

#	Time	Username	Problem	Language	Result	Execution time	Memory
914565		qin	Power Plant (JOI20_power)	C++17	100 / 100	137 ms	23860 KiB

power

#include <bits/stdc++.h>
#define fi first
#define se second
#define ssize(x) int(x.size())
#define pn printf("\n");
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define vv vector
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
int inf = 2e09; ll infll = 2e18; int mod = 119<<23|1;
struct graph{
		vector<vector<int>> g;
		vector<int> dp, pp;
		void init(int n){
				g.resize(n+1), dp.resize(n+1), pp.resize(n+1);
		}
		void add_edge(int a, int b){ g[a].emplace_back(b), g[b].emplace_back(a); }
		int result = 0;
		void dfs(int x, int par){
				int sum = 0;
				for(int u : g[x]) if(u != par) dfs(u, x), sum += dp[u];
				if(!pp[x]){ dp[x] = max(sum, 0), result = max(result, dp[x]); return; }
				for(int u : g[x]) result = max(result, dp[u]+1);
				dp[x] = max(sum-1, 1), result = max(result, dp[x]);
		}
};
void answer(){
		int n; scanf("%d", &n);
		graph g; g.init(n);
		for(int i = 0; i < n-1; ++i){
				int a, b; scanf("%d%d", &a, &b);
				g.add_edge(a, b);
		}
		char c = getchar_unlocked();
		for(int i = 1; i <= n; ++i) c = getchar_unlocked(), g.pp[i] = c-'0';
		g.dfs(1, 0);
		printf("%d\n", g.result);
}
int main(){
		int T = 1;
		for(++T; --T; ) answer();
		return 0;
}

Compilation message (stderr)

power.cpp: In function 'void answer()':
power.cpp:30:15: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   int n; scanf("%d", &n);
      |          ~~~~~^~~~~~~~~~
power.cpp:33:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     int a, b; scanf("%d%d", &a, &b);
      |               ~~~~~^~~~~~~~~~~~~~~~

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