Submission #882269

#	Time	Username	Problem	Language	Result	Execution time	Memory
882269		rainboy	DEL13 (info1cup18_del13)	C11	100 / 100	9 ms	1368 KiB

del13

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

#define N	100000

int main() {
	int t;

	scanf("%d", &t);
	while (t--) {
		static int ii[N], pp[N + 1];
		int n, m, k, h, i, j, l, r;

		scanf("%d%d", &n, &m);
		for (h = 0; h < m; h++)
			scanf("%d", &ii[h]), ii[h]--;
		memset(pp, -1, (n + 1) * sizeof *pp), pp[0] = -2;
		for (h = 0; h < m; h++) {
			l = h == 0 ? 0 : ii[h - 1] + 1, r = h + 1 == m ? n : ii[h + 1];
			for (i = l; i < ii[h]; i++)
				if (pp[i] != -1) {
					for (j = ii[h] + 2; j <= r; j++)
						if (j % 2 == (h + 1) % 2)
							pp[j] = i;
					break;
				}
			if (pp[ii[h]] != -1)
				pp[ii[h] + 1] = ii[h];
		}
		if (pp[n] == -1) {
			printf("-1\n");
			continue;
		}
		printf("%d\n", (n - m) / 2);
		for (h = m - 1, r = n; h >= 0; h--) {
			l = pp[r], r--, i = ii[h];
			if (i - l <= r - i) {
				k = (r + l) / 2 - i, j = i + k + 1;
				while (k--)
					printf("%d ", j + 1);
				k = i - l;
				while (k--)
					printf("%d ", i + 1);
			} else {
				k = i - (r + l) / 2, j = i - k - 1;
				while (k--)
					printf("%d ", j + 1);
				k = r - i;
				while (k--)
					printf("%d ", i + 1);
			}
			r = l;
		}
		printf("\n");
	}
	return 0;
}

Compilation message (stderr)

del13.c: In function 'main':
del13.c:9:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |  scanf("%d", &t);
      |  ^~~~~~~~~~~~~~~
del13.c:14:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |   scanf("%d%d", &n, &m);
      |   ^~~~~~~~~~~~~~~~~~~~~
del13.c:16:4: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |    scanf("%d", &ii[h]), ii[h]--;
      |    ^~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 15 / 15
• Subtask 4: 25 / 25
• Subtask 5: 30 / 30