제출 #683074

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
683074		rainboy	Sparklers (JOI17_sparklers)	C11	0 / 100	1 ms	212 KiB

sparklers

#include <stdio.h>

#define N	100000
#define INF	0x3f3f3f3f

long long min(long long a, long long b) { return a < b ? a : b; }

int solve(int *xx, int n, int i, int t, int s) {
	int l, r;
	long long x;

	l = r = i, x = min((long long) t * s * 2, INF);
	while (l > 0 || r + 1 < n)
		if (r + 1 == n || l > 0 && xx[l] - xx[l - 1] < xx[r + 1] - xx[r]) {
			x -= xx[l] - xx[l - 1];
			if (x < 0)
				return 0;
			l--, x = min(x + (long long) t * s * 2, INF);
		} else {
			x -= xx[r + 1] - xx[r];
			if (x < 0)
				return 0;
			r++, x = min(x + (long long) t * s * 2, INF);
		}
	return 1;
}

int main() {
	static int xx[N];
	int n, i_, t, i, lower, upper;

	scanf("%d%d%d", &n, &i_, &t), i_--;
	for (i = 0; i < n; i++)
		scanf("%d", &xx[i]);
	lower = -1, upper = INF;
	while (upper - lower > 1) {
		int s = (lower + upper) / 2;

		if (solve(xx, n, i_, t, s))
			upper = s;
		else
			lower = s;
	}
	printf("%d\n", upper);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

sparklers.c: In function 'solve':
sparklers.c:14:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   14 |   if (r + 1 == n || l > 0 && xx[l] - xx[l - 1] < xx[r + 1] - xx[r]) {
      |                     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sparklers.c: In function 'main':
sparklers.c:32:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |  scanf("%d%d%d", &n, &i_, &t), i_--;
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
sparklers.c:34:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |   scanf("%d", &xx[i]);
      |   ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50