Submission #1167128

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167128		SmuggingSpun	Money (IZhO17_money)	C++20	100 / 100	637 ms	63060 KiB

money

#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
template<class T>void minimize(T& a, T b){
    if(a > b){
        a = b;
    }
}
int n;
namespace sub12{
    void solve(){
        vector<int>a(n);
        for(int& x : a){
            cin >> x;
        }
        int ans = n;
        for(int mask = (1 << (n - 1)) - 2; mask > -1; mask--){
            vector<pair<int, int>>range(1, make_pair(0, 0));
            bool flag = true;
            for(int i = 1; i < n; i++){
                if(1 << (i - 1) & mask){
                    range.emplace_back(i, i);
                }
                else{
                    if(a[i] < a[range.back().second]){
                        flag = false;
                        break;
                    }
                    range.back().second = i;
                }
            }
            if(flag && range.size() < ans){
                vector<int>b;
                for(auto& [l, r] : range){
                    if(b.empty()){
                        b = vector<int>(a.begin() + l, a.begin() + r + 1);
                        continue;
                    }
                    if(a[r] <= b[0]){
                        b.insert(b.begin(), a.begin() + l, a.begin() + r + 1);
                    }
                    else if(a[l] >= b.back()){
                        b.insert(b.end(), a.begin() + l, a.begin() + r + 1);
                    }
                    else{
                        flag = false;
                        for(int i = 0; i + 1 < b.size() && !flag; i++){
                            if(b[i] <= a[l] && b[i + 1] >= a[r]){
                                b.insert(b.begin() + i + 1, a.begin() + l, a.begin() + r + 1);
                                flag = true;
                            }
                        }
                        if(!flag){
                            break;
                        }
                    }
                }
                if(flag){
                    ans = range.size();
                }
            }
        }
        cout << ans;
    }
}
namespace sub3{
    void solve(){
        vector<int>a(n + 1), dp(n + 1, n);
        for(int i = 1; i <= n; i++){
            cin >> a[i];
        }
        vector<vector<int>>b(n + 1);
        for(int i = 1; i <= n; i++){
            b[i] = b[i - 1];
            b[i].emplace_back(a[i]);
            for(int j = int(b[i].size() - 1); j > 0 && b[i][j] < b[i][j - 1]; j--){
                swap(b[i][j], b[i][j - 1]);
            }
        }
        dp[0] = 0;
        for(int i = 1; i <= n; i++){
            for(int j = i; j > 0; j--){
                if(j < i && a[j] > a[j + 1]){
                    break;
                }
                if(b[j - 1].empty() || b[j - 1][0] >= a[i] || b[j - 1].back() <= a[j] || b[j - 1][upper_bound(b[j - 1].begin(), b[j - 1].end(), a[j]) - b[j - 1].begin()] >= a[i]){
                    minimize(dp[i], dp[j - 1] + 1);
                }
            }
        }
        cout << dp[n];
    }
}
namespace sub4{
    const int lim = 1e6 + 5;
    const int INF = 1e9;
    int a[lim], right[lim], left[lim], dp[lim];
    void solve(){
        set<int>s;
        s.insert(right[left[0] = a[0] = dp[0] = 0] = INF);
        for(int i = 1; i <= n; i++){
            cin >> a[i];
            left[i] = (a[i] >= a[i - 1] ? left[i - 1] : i);
        }
        for(int i = 1; i < n; i++){
            s.insert(a[i]);
            right[i] = *s.upper_bound(a[i + 1]);
        }
        for(int i = 1; i <= n; i++){
            int low = left[i], high = i, p;
            while(low <= high){
                int mid = (low + high) >> 1;
                if(right[mid - 1] >= a[i]){
                    high = (p = mid) - 1;
                }
                else{
                    low = mid + 1;
                }
            }
            dp[i] = dp[p - 1] + 1;
        }
        cout << dp[n];
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n;
    if(n <= 20){
        sub12::solve();
    }
    else if(n <= 300){
        sub3::solve();
    }
    else{
        sub4::solve();
    }
}

Compilation message (stderr)

money.cpp: In function 'int main()':
money.cpp:128:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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