Submission #57110

#	Time	Username	Problem	Language	Result	Execution time	Memory
57110		Benq	Money (IZhO17_money)	C++14	100 / 100	746 ms	96192 KiB

money

#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;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

template<class T, int SZ> struct BIT {
    T bit[SZ+1];
    
    BIT() { memset(bit,0,sizeof bit); }
    
    void upd(int k, T val) { // add val to index k
        for( ;k <= SZ; k += (k&-k)) bit[k] += val;
    }
    
    int getFst(int x) {
        int cur = 0;
        F0Rd(i,20) if ((cur^(1<<i)) <= SZ && bit[cur^(1<<i)] < x) {
            x -= bit[cur^(1<<i)];
            cur ^= (1<<i);
        }
        return cur+1;
    }
    
    T query(int k) {
        T temp = 0;
        for (;k > 0;k -= (k&-k)) temp += bit[k];
        return temp;
    }
    T query(int l, int r) { return query(r)-query(l-1); } // range query [l,r]
};

BIT<int,1000000> T;

int n;
bool fixe = 0;

bool nex(int a, int b) {
    int x = T.query(b-1), y = T.query(b);
    if (y-x > 1) {
        if (a == b) return 1;
        if (fixe == 1) return 0;
    }
    int z = T.getFst(x);
    return a == z;
}

vi v;

void stuff() {
    T.upd(v.back(),-1);
    v.pop_back();
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n; v.resize(n);
    F0R(i,n) {
        cin >> v[i];
        T.upd(v[i],1);
    }
    int ans = 0;
    while (sz(v)) {
        fixe = 0;
        while (sz(v) > 1 && nex(v[sz(v)-2],v[sz(v)-1])) {
            if (v[sz(v)-2] != v[sz(v)-1]) fixe = 1;
            stuff();
        }
        stuff(); ans ++;
    }
    cout << ans;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55