Submission #102079

#	Time	Username	Problem	Language	Result	Execution time	Memory
102079		ainta	Designated Cities (JOI19_designated_cities)	C++17	100 / 100	836 ms	48708 KiB

designated_cities

#include<cstdio>
#include<algorithm>
#include<vector>
#define N_ 201000
#define SZ 262144
#define pii pair<int,int>
#define X first
#define Y second
using namespace std;
vector<int>E[N_];
int n, chk[N_], cnt;
long long S[N_], Far[N_], Res[N_];
struct Edge {
	int e, l;
}Ed[N_*2];
void Add_Edge(int a, int b, int c) {
	E[a].push_back(cnt);
	Ed[cnt++] = { b,c };
}
void DFS1(int a, int pp) {
	for (auto &t : E[a]) {
		int x = Ed[t].e, l = Ed[t].l;
		if (x == pp)continue;
		DFS1(x, a);
		Far[a] = max(Far[a], Far[x] + l);
		S[a] += S[x] + l;
	}
}
void DFS2(int a, int pp, long long f) {
	int pv1 = -1, pv2 = -1;
	long long f1 = 0, f2 = 0;
	Far[a] = max(Far[a], f);
	for (auto &t : E[a]) {
		int x = Ed[t].e, l = Ed[t].l;
		if (x == pp)continue;
		S[x] = S[a] - l + Ed[t ^ 1].l;
		if (f1 <= Far[x] + l) {
			pv2 = pv1, f2 = f1;
			pv1 = x, f1 = Far[x] + l;
		}
		else if (f2 <= Far[x] + l) {
			pv2 = x, f2 = Far[x] + l;
		}
	}
	for (auto &t : E[a]) {
		int x = Ed[t].e, l = Ed[t].l;
		if (x == pp)continue;
		if (x == pv1) {
			DFS2(x, a, Ed[t ^ 1].l + max(f2,f));
		}
		else {
			DFS2(x, a, Ed[t ^ 1].l + max(f1,f));
		}
	}
}
int Num[N_], End[N_], ReNum[N_], par[N_], pL[N_];
long long DD[N_];
struct Tree {
	long long Mx[SZ + SZ], K[SZ + SZ];
	void UDT(int nd) {
		Mx[nd] = max(Mx[nd * 2], Mx[nd * 2 + 1]);
	}
	void init(int nd, int b, int e) {
		K[nd] = 0;
		if (b == e) {
			Mx[nd] = DD[ReNum[b]];
			return;
		}
		int m = (b + e) >> 1;
		init(nd * 2, b, m);
		init(nd * 2 + 1, m + 1, e);
		UDT(nd);
	}
	void Add2(int nd, long long x) {
		Mx[nd] += x;
		K[nd] += x;
	}
	void Spread(int nd) {
		Add2(nd * 2, K[nd]);
		Add2(nd * 2 + 1, K[nd]);
		K[nd] = 0;
	}
	void Add(int nd, int b, int e, int s, int l, long long x) {
		if (s > l)return;
		if (b == s && e == l) {
			Add2(nd, x);
			return;
		}
		int m = (b + e) >> 1;
		Spread(nd);
		if (s <= m)Add(nd * 2, b, m, s, min(m, l), x);
		if (l > m)Add(nd * 2 + 1, m + 1, e, max(m + 1, s), l, x);
		UDT(nd);
	}
	int Find(int nd, int b, int e) {
		if (Mx[nd] == 0)return 0;
		if (b == e)return ReNum[b];
		int m = (b + e) >> 1;
		Spread(nd);
		if (Mx[nd * 2] == Mx[nd])return Find(nd * 2, b, m);
		return Find(nd * 2 + 1, m + 1, e);
	}
}TT;
void DFS3(int a, int pp, long long d) {
	Num[a] = ++cnt;
	ReNum[cnt] = a;
	DD[a] = d;
	par[a] = pp;
	for (auto &t : E[a]) {
		int x = Ed[t].e, l = Ed[t].l;
		if (x == pp)continue;
		pL[x] = l;
		DFS3(x, a, d+l);
	}
	End[a] = cnt;
}
int main() {
	//freopen("input.txt", "r", stdin);
	int i, a, b, c, d;
	scanf("%d", &n);
	for (i = 1; i < n; i++) {
		scanf("%d%d%d%d", &a, &b, &c, &d);
		Add_Edge(a, b, c);
		Add_Edge(b, a, d);
	}
	DFS1(1, 0);
	DFS2(1, 0, 0);
	for (i = 1; i <= n; i++)Res[i] = 1e18;
	for (i = 1; i <= n; i++)Res[1] = min(Res[1], S[i]);
	int pv = -1;
	for (i = 1; i <= n; i++) {
		if (Res[2] > S[i] - Far[i]) {
			Res[2] = S[i] - Far[i];
			pv = i;
		}
	}

	int root = pv;
	cnt = 0;
	DFS3(root, 0, 0);
	TT.init(1, 1, n);
	for (i = 1; i <= n; i++)chk[i] = 0;
	chk[root] = 1;
	long long ss = S[root];
	for (i = 2; i <= n; i++) {
		ss -= TT.Mx[1];
		Res[i] = min(Res[i], ss);
		int a = TT.Find(1, 1, n);
		if (!a) continue;
		while (!chk[a]) {
			TT.Add(1, 1, n, Num[a], End[a], -pL[a]);
			chk[a] = 1;
			a = par[a];
		}
	}
	int Q;
	scanf("%d", &Q);
	while (Q--) {
		scanf("%d", &a);
		printf("%lld\n", Res[a]);
	}
}

Compilation message (stderr)

designated_cities.cpp: In function 'void DFS2(int, int, long long int)':
designated_cities.cpp:46:20: warning: unused variable 'l' [-Wunused-variable]
   int x = Ed[t].e, l = Ed[t].l;
                    ^
designated_cities.cpp:30:16: warning: variable 'pv2' set but not used [-Wunused-but-set-variable]
  int pv1 = -1, pv2 = -1;
                ^~~
designated_cities.cpp: In function 'int main()':
designated_cities.cpp:120:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:122:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d%d", &a, &b, &c, &d);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
designated_cities.cpp:157:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:159:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a);
   ~~~~~^~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 9 / 9
• Subtask 4: 17 / 17
• Subtask 5: 17 / 17
• Subtask 6: 44 / 44