Submission #894670

#	Time	Username	Problem	Language	Result	Execution time	Memory
894670		AgentPengin	즐거운 채소 기르기 (JOI14_growing)	C++14	100 / 100	62 ms	11212 KiB

growing

/**
 *    author:  AgentPengin ( Độc cô cầu bại )
 *    created: 23.12.2022 10:08:02
 *    too lazy to update time
**/
#include<bits/stdc++.h>

#define EL '\n'
#define fi first
#define se second
#define NAME "TASK"
#define ll long long
#define lcm(a,b) (a/gcd(a,b))*b
#define db(val) "["#val" = " << (val) << "] "
#define bend(v) (v).begin(),(v).end()
#define sz(v) (int)(v).size()
#define ex exit(0)

using namespace std;

const ll mod = 1e9 + 7;
const int inf = 0x1FFFFFFF;
const int MAXN = 3e5 + 5;

int n,a[MAXN],bit[MAXN];
vector<pair<int,int>> v;

void update(int x) {
	for (;x <= n;x+=x&-x) bit[x]++;
}

int get(int x) {
	int res = 0;
	for (;x;x-=x&-x) res += bit[x];
	return res;
}

signed main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    if (ifstream(NAME".inp")) {
        freopen(NAME".inp","r",stdin);
        freopen(NAME".out","w",stdout);
    }
    cin >> n;
    for (int i = 1;i <= n;i++) cin >> a[i];
    for (int i = 1;i <= n;i++) {
    	v.push_back(make_pair(a[i],i));
    }
    sort(bend(v),greater<pair<int,int>>());
	int ptr = 0;
	ll ans = 0;
	for (auto x : v) {
		while(v[ptr].fi > x.fi) {
			update(v[ptr].se);
			++ptr;
		}
		ans += min((ll)get(x.se - 1),(ll)get(n) - get(x.se));
	}
	cout << ans;
    cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
    return 0;
}
// agent pengin wants to take apio (with anya-san)

Compilation message (stderr)

growing.cpp: In function 'int main()':
growing.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |         freopen(NAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
growing.cpp:42:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |         freopen(NAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 15 / 15
• Subtask 4: 55 / 55