Submission #833941

#	Time	Username	Problem	Language	Result	Execution time	Memory
833941		josanneo22	Two Currencies (JOI23_currencies)	C++17	28 / 100	189 ms	42940 KiB

currencies

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ld long double
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define ar array
const int N=1e5+500,K=25;
int cnt = 0, cur = 0, tin[N], tout[N], sp[N][K];
vector<pair<int,int>> g[N];
int dep[N], w[N];
void dfs(int u, int p){
    tin[u] = cur++;
    sp[u][0] = p;
    for(int i = 1; i < K; i++)
        sp[u][i] = sp[sp[u][i-1]][i-1];
    for(auto x : g[u]){
        if(x.fi == p) continue;
        dep[x.fi] = dep[u]+w[x.se];
        dfs(x.fi,u);
    }
    tout[u] = cur++;
}
bool is_anc(int u, int v){
    return (tin[u] <= tin[v] && tout[v] <= tout[u]);
}
int lca(int u, int v){
    if(is_anc(u,v)) return u;
    if(is_anc(v,u)) return v;
    for(int i = K-1; i >= 0; i--)
        if(!is_anc(sp[u][i], v)) u = sp[u][i];
    return sp[u][0];
}
void solve(){
    int n,m,q; cin >> n >> m >> q;
    for (int i = 0; i < n-1; ++i)
    {
        int a,b; cin >> a >> b;
        a--,b--;
        g[a].pb(mp(b,i));
        g[b].pb(mp(a,i));
    }
    for (int i = 0; i < m; ++i)
    {
        int p, c;
        cin >> p >> c;
        p--;
        cnt = c;
        w[p] += c;
    }
    dfs(0,0);
    while(q--){
        int s,t,au_have,ag;
        cin >> s >> t >> au_have >> ag;
        s--,t--;
        int l = lca(s,t);
        int sm = dep[s]+dep[t]-2*dep[l];
        int au = sm/cnt - ag/cnt;
        if(au <= 0) cout << au_have <<'\n';
        else if(au <= au_have) cout << au_have-au << '\n';
        else cout << -1 << '\n'; 
    }
}
signed main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	clock_t tStart = clock();
	int local=0,multi=0,debug=1,tt=1;
	if(local){
	    freopen("input.txt","r",stdin);
	    freopen("output.txt","w",stdout);
	}	
	if(multi) cin>>tt;
	for(int i=1;i<=tt;i++){
		if(debug && multi && local) cout<<"样例 "<<i<<'\n';
		solve();
 	}
	fprintf(stderr, "\n>> Runtime: %.10fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
}

Compilation message (stderr)

currencies.cpp: In function 'int main()':
currencies.cpp:74:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |      freopen("input.txt","r",stdin);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
currencies.cpp:75:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |      freopen("output.txt","w",stdout);
      |      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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