제출 #742209

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
742209		rainboy	Schools (IZhO13_school)	C11	100 / 100	156 ms	8752 KiB

school

#include <stdio.h>
#include <string.h>

#define N	300000
#define INF	0x3f3f3f3f

unsigned int X = 12345;

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

int aa[N], bb[N], iia[N], iib[N], n, k;

int *xx;

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;
	}
}

long long x; int ka;

void solve(int c) {
	static char used[N];
	int h, i, j, ia, ib;

	memset(used, 0, n * sizeof *used);
	i = 0, j = 0, x = 0, ka = 0;
	for (h = 0; h < k; h++) {
		while (used[iia[i]])
			i++;
		while (used[iib[j]])
			j++;
		ia = iia[i], ib = iib[j];
		if (aa[ia] - c > bb[ib])
			used[ia] = 1, x += aa[ia] - c, ka++;
		else
			used[ib] = 1, x += bb[ib];
	}
}

int main() {
	int ka_, kb_, i, lower, upper, c;

	scanf("%d%d%d", &n, &ka_, &kb_), k = ka_ + kb_;
	for (i = 0; i < n; i++)
		scanf("%d%d", &aa[i], &bb[i]);
	for (i = 0; i < n; i++)
		iia[i] = i;
	xx = aa, sort(iia, 0, n);
	for (i = 0; i < n; i++)
		iib[i] = i;
	xx = bb, sort(iib, 0, n);
	lower = -INF, upper = INF;
	while (upper - lower > 1) {
		c = (lower + upper) / 2;
		solve(c);
		if (ka <= ka_)
			upper = c;
		else
			lower = c;
	}
	solve(upper);
	printf("%lld\n", x + (long long) upper * ka_);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

school.c: In function 'main':
school.c:60:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |  scanf("%d%d%d", &n, &ka_, &kb_), k = ka_ + kb_;
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
school.c:62:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d%d", &aa[i], &bb[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100