Submission #1096191

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096191		Sunbae	Putovanje (COCI20_putovanje)	C++17	110 / 110	50 ms	41412 KiB

putovanje

#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
const int N = 2e5 + 5, M = 4e5 + 5;
vector<int> g[N];
tuple<int,int,int,int> e[N];
int E[M], T[M], mn[N], ST[M][20], m;
ll d[N];
void dfs(int u){
	E[m++] = u;
	for(int v: g[u]){
		g[v].erase(find(g[v].begin(), g[v].end(), u));
		dfs(v); E[m++] = u;
	}
}
int get_lca(int u, int v){
	if(mn[u] > mn[v]) swap(u, v);
	int j = 31 - __builtin_clz(mn[v] - mn[u] + 1);
	return T[min(ST[mn[u]][j], ST[mn[v]-(1<<j)+1][j])];
}
void efs(int u){
	for(int v: g[u]) efs(v), d[u] += d[v];
}
signed main(){
	int n; scanf("%d", &n);
	for(int i = 0, u, v, w[2]; i<n-1; ++i){
		scanf("%d %d %d %d", &u, &v, w, w+1); --u; --v;
		g[u].push_back(v); g[v].push_back(u);
		e[i] = {u, v, w[0], w[1]};
	}
	dfs(0);
	for(int i = m-1; i>=0; --i) T[mn[E[i]] = i] = E[i];
	for(int i = 0; i<m; ++i) ST[i][0] = mn[E[i]];
	for(int j = 1; j<32 - __builtin_clz(m); ++j) for(int i = 0; i+(1<<j)-1<m; ++i) ST[i][j] = min(ST[i][j-1], ST[i+(1<<(j-1))][j-1]);
	for(int i = 0; i<n-1; ++i){
		int u = i, v = i+1, lca = get_lca(u, v);
		++d[u]; ++d[v]; d[lca] -= 2;
	}	
	efs(0);
	ll tot = 0;
	for(int i = 0, u, v, w[2]; i<n-1; ++i){
		tie(u, v, w[0], w[1]) = e[i];
		if(mn[u] > mn[v]) swap(u, v);
		tot += min(w[0] * 1ll * d[v], 1ll * w[1]);
	}
	printf("%lld", tot);
}

Compilation message (stderr)

putovanje.cpp: In function 'int main()':
putovanje.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |  int n; scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
putovanje.cpp:27:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |   scanf("%d %d %d %d", &u, &v, w, w+1); --u; --v;
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 65 / 65