Submission #742008

#	Time	Username	Problem	Language	Result	Execution time	Memory
742008		vjudge1	Fireworks (APIO16_fireworks)	C++17	0 / 100	25 ms	47220 KiB

fireworks

// #pragma GCC target( "sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
// #pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")  
#include<bits/stdc++.h>
#define f first
#define s second
#define pb push_back
#define sz(x) (int)x.size()
#define bit(a, i) ((a>>i)&1)

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

const int K = 800;
const ll inf = 1e18;
const int mod = 1e9 + 7;
const int maxn = 1e6 + 100;

int n, m;
ll ans, OK;
ll c[maxn];
vector<ll>e[maxn];
vector<pii>g[maxn];

void dfs(int v, int pr, ll timer){
	bool ok = 0;
	for(pii to: g[v]){
		if(to.f != pr){
			ok = 1;
			dfs(to.f, v, timer+to.s);
			for(auto to1: e[to.f]) e[v].pb(to1);
		}
	}
	if(v > n) {
		e[v].pb(timer);
		c[v] = timer;
	}
	sort(e[v].begin(), e[v].end());
}

void count(int x, ll y, int v, int pr){
	bool ok = 0;
	for(pii to: g[v]){
		int u = to.f;
		if(u == pr) continue;
		ok = 1;
		if(e[u][0]+y >= x){
			ll nwy = y - min(e[u][0]+y-x, to.s*1ll);
			ans += min(e[u][0]+y-x, to.s*1ll);
			count(x, nwy, u, v);
			continue;
		}
		if(e[u].back()+y <= x){
			ll nwy = x-e[u].back();
			ans += x-(e[u].back()+y);
			count(x, nwy, u, v);
			continue;
		}
		count(x, y, u, v);
	}
	if(v > n && c[v]+y != x) OK = 0;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> n >> m;
    for(int i=2; i<=n+m; i++){
    	int v, w; cin >> v >> w;
    	g[v].pb({i, w});
	}
	dfs(1, 0, 0);
	ll sum = inf;
	for(int i=0; i<=500; i++){
		OK = 1;
		ans = 0;
		count(i, 0, 1, 0);
		if(OK) {
			sum = min(sum, ans);
		}
	}
	cout << sum;
}

Compilation message (stderr)

fireworks.cpp: In function 'void dfs(int, int, ll)':
fireworks.cpp:26:7: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
   26 |  bool ok = 0;
      |       ^~
fireworks.cpp: In function 'void count(int, ll, int, int)':
fireworks.cpp:42:7: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
   42 |  bool ok = 0;
      |       ^~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45