Submission #25785

#	Time	Username	Problem	Language	Result	Execution time	Memory
25785		kajebiii	즐거운 채소 기르기 (JOI14_growing)	C++14	30 / 100	23 ms	10568 KiB

growing

#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int (i)=0;(i)<(int)(n);(i)++)
#define REPO(i,n) for(int (i)=1; (i)<=(int)(n); (i)++)
#define SZ(v) ((int)(v).size())
#define ALL(v) (v).begin(),(v).end()
#define one first
#define two second
typedef long long ll;
typedef pair<int, int> pi;
const int INF = 0x3f2f1f0f;
const ll LINF = 1ll * INF * INF;

const int MAX_N = 3e5 + 100;

struct BIT {
	int val[MAX_N];
	BIT() {
		for(int i=0; i<MAX_N; i++) val[i] = 0;
	}
	void update(int v, int k) {
		for(v++; v<MAX_N; v+=v&-v) val[v] += k;
	}
	int getSum(int v) {
		int res = 0;
		for(v++; v; v-=v&-v) res += val[v];
		return res;
	}
	int getSum(int a, int b) {
		return getSum(b) - getSum(a-1);
	}
};
int N, Nr[MAX_N];
ll CntL[MAX_N], CntR[MAX_N];
vector<int> Co;
int main() {
	cin >> N; REPO(i, N) scanf("%d", &Nr[i]), Co.push_back(Nr[i]);
	sort(ALL(Co)); Co.erase(unique(ALL(Co)), Co.end());
	int cN = SZ(Co);
	for(int i=1; i<=N; i++) Nr[i] = lower_bound(ALL(Co), Nr[i]) - Co.begin();
	BIT bitL, bitR;
	for(int i=1; i<=N; i++) {
		CntL[i] = CntL[i-1] + bitL.getSum(Nr[i]+1, cN-1);
		bitL.update(Nr[i], 1);
	}
	for(int i=N; i>=1; i--) {
		CntR[i] = CntR[i+1] + bitR.getSum(Nr[i]+1, cN-1);
		bitR.update(Nr[i], 1);
	}
	ll ans = LINF;
	for(int i=0; i<=N; i++) ans = min(ans, CntL[i] + CntR[i+1]);
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

growing.cpp: In function 'int main()':
growing.cpp:39:63: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  cin >> N; REPO(i, N) scanf("%d", &Nr[i]), Co.push_back(Nr[i]);
                                                               ^

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 15
• Subtask 4: 0 / 55