Submission #987836

#	Time	Username	Problem	Language	Result	Execution time	Memory
987836		steveonalex	Money (IZhO17_money)	C++17	100 / 100	1309 ms	73760 KiB

money

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 1e6 + 69, INF = 1e9 + 69;
int a[N];
int sum[N];
int dp[N];

struct SegmentTree{
    int n;
    vector<int> a;

    SegmentTree(int _n){
        n = _n;
        a.resize(n * 2 + 2, INF);
    }

    int get(int i){
        i += n; 
        int ans = INF;
        while(i > 0){
            minimize(ans, a[i]);
            i >>= 1;
        }
        return ans;
    }

    void update(int l, int r, int v){
        l += n; r += n + 1;
        while(l < r){
            if (l & 1) minimize(a[l++], v);
            if (r & 1) minimize(a[--r], v);
            l >>= 1; r >>= 1;
        }
    }
};

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int n; cin >> n;
    for(int i = 1; i<=n; ++i) cin >> a[i];

    for(int i = 2; i<=n; ++i) sum[i] = (sum[i-1] + (a[i] >= a[i-1]));
    for(int i = 1; i<=n; ++i) dp[i] = INF;

    set<int> S;
    a[0] = INF;
    SegmentTree st(n);
    for(int i = 0; i<n; ++i){
        if (i > 0) dp[i] = st.get(i);
        S.insert(a[i]);
        int cap = *S.upper_bound(a[i+1]);
        int l = i + 1, r = n;
        while(l < r){   
            int mid = (l + r + 1) >> 1;
            if (sum[mid] - sum[i+1] == mid - (i+1) && a[mid] <= cap) l = mid;
            else r = mid - 1;
        }
        st.update(i + 1, l, dp[i] + 1);
    }
    dp[n] = st.get(n);

    cout << dp[n] << "\n";



    return 0;
}

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