Submission #1276917

#	Time	Username	Problem	Language	Result	Execution time	Memory
1276917		icebear	Money (IZhO17_money)	C++20	100 / 100	930 ms	55228 KiB

money

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

typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;

template<class T>
    bool minimize(T &a, const T &b) {
        if (a > b) return a = b, true;
        return false;
    }

template<class T>
    bool maximize(T &a, const T &b) {
        if (a < b) return a = b, true;
        return false;
    }

#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define FORR(i,a,b) for(int i=(a); i>=(b); --i)
#define REP(i, n) for(int i=0; i<(n); ++i)
#define RED(i, n) for(int i=(n)-1; i>=0; --i)
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define task "gen"

const int MOD = 1e9 + 7;
const int inf = 0x3f3f3f3f;
const ll INF = 1e18 + 27092008;
const int N = 1e6 + 5;
int n, a[N], f[N];

void init(void) {
    cin >> n;
    FOR(i, 1, n) cin >> a[i];
}

void process(void) {
    memset(f, 0x3f, sizeof f);
    f[0] = 0;
    set<ii> fs;
    set<int> s;
    int j = 1;
    FOR(i, 0, n) {
        while(!fs.empty() && fs.begin()->se == i) fs.erase(*fs.begin());
        if (!fs.empty()) f[i] = fs.begin()->fi;
        if (f[i] == inf) continue;

        maximize(j,i+2);
        while(j <= n && a[j] >= a[j-1]) j++;
        auto it = s.upper_bound(a[i+1]);
        int val = (it == s.end() ? inf : *it);

        int low = i + 1, high = j - 1, res = j - 1;
        while(low <= high) {
            int mid = (low + high) >> 1;
            if (a[mid] <= val) res = mid, low = mid + 1;
            else high = mid - 1;
        }
        s.insert(a[i+1]);
        fs.insert(mp(f[i] + 1, res + 1));
    }

    cout << f[n] << '\n';
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int tc = 1;
//    cin >> tc;
    while(tc--) {
        init();
        process();
    }
    return 0;
}

Compilation message (stderr)

money.cpp: In function 'int main()':
money.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
money.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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