Submission #993584

---

Source Code Expand

#include <stdio.h>

#define min(a, b) ((a) < (b) ? a : b)

int cnt[100000];
int cnt2[100001];

int main(void) {
	int i;
	int n, m;
	int ans;

	scanf("%d %d", &n, &m);
	for (i = 0; i < n; i++) {
		int x;
		scanf("%d", &x);
		cnt[x % m]++;
		cnt2[x]++;
	}

	ans = 0;
	for (i = 1; i <= 100000; i++) {
		const int me = i % m, oppo = (m - me) % m;
		if (oppo != me)
			if (cnt[me] > cnt[oppo]) {
				const int down = min(cnt2[i] / 2, (cnt[me] - cnt[oppo]) / 2);
				cnt[i % m] -= down * 2;
				ans += down;
			}
	}

	for (i = 0; i < m; i++) {
		if ((m - i) % m == i) {
			ans += cnt[i] / 2;
			cnt[i] %= 2;
		} else {
			const int common = min(cnt[i], cnt[m - i]);
			ans += common;
			cnt[i] -= common;
			cnt[m - i] -= common;
		}
	}

	printf("%d\n", ans);

	return 0;
}

Submission Info

Compile Error

./Main.c: In function ‘main’:
./Main.c:13:2: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ^
./Main.c:16:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &x);
   ^

Judge Result