Submission #944494

#	Time	Username	Problem	Language	Result	Execution time	Memory
944494		rainboy	공장 (KOI13_factory)	C11	20 / 20	243 ms	18772 KiB

factory

#include <stdio.h>

#define N	500000

unsigned int X = 12345;

int rand_() {
	return (X *= 3) >> 1;
}

int *ww;

void sort(int *ii, int l, int r) {
	while (l < r) {
		int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;

		while (j < k)
			if (ww[ii[j]] == ww[i_])
				j++;
			else if (ww[ii[j]] < ww[i_]) {
				tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
				i++, j++;
			} else {
				k--;
				tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
			}
		sort(ii, l, i);
		l = k;
	}
}

int ft[N];

void update(int i, int n) {
	while (i < n) {
		ft[i]++;
		i |= i + 1;
	}
}

int query(int i) {
	int x = 0;

	while (i >= 0) {
		x += ft[i];
		i &= i + 1, i--;
	}
	return x;
}

int main() {
	static int aa[N], bb[N], ii[N], jj[N], jj_[N];
	int n, h, i, j;
	long long ans;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d", &aa[i]);
	for (j = 0; j < n; j++)
		scanf("%d", &bb[j]);
	for (i = 0; i < n; i++)
		ii[i] = i;
	ww = aa, sort(ii, 0, n);
	for (j = 0; j < n; j++)
		jj[j] = j;
	ww = bb, sort(jj, 0, n);
	for (h = 0; h < n; h++)
		jj_[ii[h]] = jj[h];
	ans = 0;
	for (i = n - 1; i >= 0; i--) {
		ans += query(jj_[i]);
		update(jj_[i], n);
	}
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

factory.c: In function 'main':
factory.c:56:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
factory.c:58:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |   scanf("%d", &aa[i]);
      |   ^~~~~~~~~~~~~~~~~~~
factory.c:60:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |   scanf("%d", &bb[j]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 2.2 / 2.2
• Subtask 2: 3.4 / 3.4
• Subtask 3: 3.8 / 3.8
• Subtask 4: 4.8 / 4.8
• Subtask 5: 5.8 / 5.8