Submission #450424

#	Time	Username	Problem	Language	Result	Execution time	Memory
450424		rainboy	Unija (COCI17_unija)	C11	100 / 100	545 ms	27076 KiB

unija

#include <stdio.h>

#define N	1000000

int max(int a, int b) { return a > b ? a : b; }

unsigned int X = 12345;

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

int xx[N], yy[N];

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 (xx[ii[j]] == xx[i_])
				j++;
			else if (xx[ii[j]] < xx[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 main() {
	static int ii[N];
	int n, i, y;
	long long ans;

	scanf("%d", &n);
	for (i = 0; i < n; i++) {
		scanf("%d%d", &xx[i], &yy[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	ans = 0, y = 0;
	for (i = n - 1; i >= 0; i--) {
		y = max(y, yy[ii[i]]);
		ans += (long long) (xx[ii[i]] - (i == 0 ? 0 : xx[ii[i - 1]])) * y;
	}
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

unija.c: In function 'main':
unija.c:39:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
unija.c:41:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |   scanf("%d%d", &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10