Submission #320171

#	Time	Username	Problem	Language	Result	Execution time	Memory
320171		Karen124	MP3 Player (CEOI10_mp3player)	C++14	10 / 100	83 ms	2924 KiB

mp3player

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
 
using namespace std;
using namespace __gnu_pbds;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
 
#define ll long long int 
#define F first
#define S second
#define pb push_back
const ll N = 1e5 + 5;
const ll LOG = 30;
const ll MOD = 1e9 + 7;
const ll INF = 1e18 + 10;
ll n, Vmax, V2, a[N], t[N], mxT, mxV1;
vector <ll> dif;
ll R_Do_Operations(ll e, ll T){
    for (ll i = n; i >= 2; i--){
        if (t[i] - t[i - 1] <= T){
            e -= a[i];
        }
        e = max(e, 0ll);
        e = min(e, Vmax);
    }
    return e;
}
ll Do_Operations(ll s, ll T){
    for (ll i = 2; i <= n; i++){
        if (t[i] - t[i - 1] <= T){
            s += a[i];
        }
        s = max(s, 0ll);
        s = min(s, Vmax);
    }  
    return s;
}
int ok(ll T){
    ll s = R_Do_Operations(V2, T);
    ll e = Do_Operations(s, T);
    return (e == V2);
}
int main (){
    cin >> n >> Vmax >> V2;
    for (ll i = 1; i <= n; i++){
        char c;
        cin >> c >> t[i];
        a[i] = ((c == '+') ? 1 : -1);
        if (i != 1) dif.pb(t[i] - t[i - 1]);
    }
    if (ok(INF)) return cout << "infinity\n", 0;
    sort(dif.begin(), dif.end());
    dif.resize(unique(dif.begin(), dif.end()) - dif.begin());
    ll l = 0, r = dif.size();
    while (l + 1 < r){
        ll mid = (l + r) / 2;
        if (!ok(dif[mid])) r = mid;
        else l = mid;
    }
    mxT = dif[r - 1];
    ll L = R_Do_Operations(V2, mxT), R = Vmax + 1;
    while (L + 1 < R){
        ll mid = (L + R) / 2;
        if (Do_Operations(mid, mxT) != V2) R = mid;
        else L = mid;
    }
    mxV1 = R - 1;
    cout << mxT << ' ' << mxV1 << '\n';
    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10