Submission #888818

#	Time	Username	Problem	Language	Result	Execution time	Memory
888818		vjudge1	Two Currencies (JOI23_currencies)	C++17	10 / 100	5058 ms	60932 KiB

currencies

#include <bits/stdc++.h>
 
#define int long long
#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
 
using namespace std;	
 
void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
int pow(int a,int b,int m){int ans=1;while(b){if(b&1){ans=(ans*a)%m;}b>>=1;a=(a*a)%m;}return ans;}
int binpow(int a,int b){int ans=1;while(b){if(b&1){ans=(ans*a);}b>>=1;a=(a*a);}return ans;}

const int N = 2e5 + 10;
 
vector <int> g[N], cost[N];

int up[N][30];
int tin[N], tout[N], ch[N], par[N], notch[N];
int timer;

void dfs(int v, int p){
	par[v] = p;
	tin[v] = timer++;
	up[v][0] = p;
	for (int i=1; i<=25; ++i)
		up[v][i] = up[up[v][i-1]][i-1];
	for(auto to : g[v]){
		if(to == p)continue;
		dfs(to, v);
	}
	tout[v] = timer++;
}

bool upper (int a, int b) {
	return tin[a] <= tin[b] && tout[a] >= tout[b];
}
bool upper2 (int a, int b) {
	return tin[a] < tin[b] && tout[a] > tout[b];
}

int lca (int a, int b) {
	if (upper (a, b))  return a;
	if (upper (b, a))  return b;
	for (int i=25; i>=0; --i)
		if (! upper (up[a][i], b))
			a = up[a][i];
	return up[a][0];
}

main(){
    ios :: sync_with_stdio(0);
    cin.tie(0);
    int n, m, q;
    cin >> n >>  m >> q;
    vector <pair <int, int> > road = {{-1, -1}};
    for(int i = 0; i < n - 1; i++){
		int a, b;
		cin >> a >> b;
		road.pb({a, b});
		g[a].pb(b);
		g[b].pb(a);
	}
	dfs(1, 1);
	for(int i = 1; i <= n; i++){
		int x = road[i].ff, y = road[i].ss; 
		if(par[x] == y){
			ch[i] = x;
			notch[i] = y;
		}else{
			ch[i] = y;
			notch[i] = x;
		}
	}
	set <int> st;
	vector <int> pref = {0};
	int mr = 0;
	for(int i = 0; i < m; i++){
		int ind, silv;
		cin >> ind >> silv;
		pref.pb(silv);
		st.insert(ind);
		mr = ch[ind];
		cost[ch[ind]].pb(silv);
	}
	sort(all(pref));
	for(int i = 1; i <= m; i++){
		pref[i] += pref[i - 1];
	}
	pref.pb(2e18);
	if((int)st.size() == 1){
		for(int i = 0; i < q; i++){
			int f, s, gold, silv;
			cin >> f >> s >> gold >> silv;
			int lc = lca(f, s);
			//cout << mr <<"====" << endl;
			if(upper2(lc, mr) && upper(mr, f) || upper(mr, s) && upper2(lc, mr)){
				int l  = -1, r = gold;
				while(l + 1 < r){
					int mid = (l + r) >> 1;
					if(pref[m - mid] <= silv)
						r = mid;
					else
						l = mid;
				}
				cout << l << endl;
			}else{
				cout << gold << endl;
			}
		}
		return 0;
	}	 	
	//cout << "====" << endl;
	for(int i = 0; i < q; i++){
		int f, s, gold, silv;
		cin >> f >> s >> gold >> silv;
		vector <int> c;
		int lc = lca(f, s);
		while(s != lc){
			for(auto x : cost[s]){
				c.pb(x);
			}
			s= par[s];
		}
		while(f != lc){
			for(auto x : cost[f]){
				c.pb(x);
			}
			f = par[f];
			
		}
			sort(all(c));
			for(auto x : c){
				if(silv >= x){
					silv -= x;
				}else{
					gold--;
				}
			}
			if(gold < 0){
				cout << "-1\n";
			}else{
				cout << gold << endl;
			}
	}
}

Compilation message (stderr)

currencies.cpp:53:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   53 | main(){
      | ^~~~
currencies.cpp: In function 'int main()':
currencies.cpp:99:22: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   99 |    if(upper2(lc, mr) && upper(mr, f) || upper(mr, s) && upper2(lc, mr)){
      |       ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
currencies.cpp: In function 'void fp(std::string)':
currencies.cpp:12:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 | void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
currencies.cpp:12:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 | void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 28
• Subtask 3: 0 / 30
• Subtask 4: 0 / 32