Submission #554370

#	Time	Username	Problem	Language	Result	Execution time	Memory
554370		Keshi	Fireworks (APIO16_fireworks)	C++17	7 / 100	1 ms	568 KiB

fireworks

//In the name of God
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const ll maxn = 512;
const ll mod = 1e9 + 7;
const ll inf = 1e15;

#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r+", stdin);freopen("output.txt", "w+", stdout);
#define pb push_back
#define Mp make_pair
#define F first
#define S second
#define Sz(x) ll((x).size())
#define all(x) (x).begin(), (x).end()

ll pw(ll a, ll b){
	ll c = 1;
	while(b){
		if(b & 1) c = c * a % mod;
		a = a * a % mod;
		b >>= 1;
	}
	return c;
}

int n, m, p[maxn], c[maxn];
vector<int> g[maxn];
ll dp[maxn][maxn];

void dfs(int v){
	for(int u : g[v]){
		dfs(u);
		for(int i = c[v]; i < maxn; i++){
			dp[v][i] += dp[u][i - c[v]];
		}
	}
	if(g[v].empty()){
		fill(dp[v], dp[v] + maxn, inf);
		dp[v][c[v]] = 0;
	}
	for(int i = 0; i < c[v]; i++){
		dp[v][i] = inf;
	}
	ll mn = inf;
	for(int i = 0; i < maxn; i++){
		dp[v][i] = min(dp[v][i], i + mn);
		mn = min(mn, dp[v][i] - i);
	}
	mn = inf;
	for(int i = maxn; i--;){
		dp[v][i] = min(dp[v][i], mn - i);
		mn = min(mn, dp[v][i] + i);
	}
	return;
}

void solve(){
	ll ans = inf;
	for(int i = 2; i <= n + m; i++){
		ll x = 0;
		for(int j = 2; j <= n + m; j++){
			x += abs(c[i] - c[j]);
		}
		ans = min(ans, x);
	}
	cout << ans << "\n";
	return;
}

int main(){
	fast_io;

	cin >> n >> m;
	for(int i = 2; i <= n + m; i++){
		cin >> p[i] >> c[i];
		g[p[i]].pb(i);
	}
	if(n == 1){
		solve();
		return 0;
	}
	dfs(1);
	ll ans = inf;
	for(int i = 0; i < maxn; i++){
		ans = min(ans, dp[1][i]);
	}
	cout << ans << "\n";
	
	return 0;
}

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