oj.uz

Submission #482446

# Submission time Handle Problem Language Result Execution time Memory
482446 2021-10-24T15:10:16 Z rainboy 3D Histogram (COCI20_histogram) C
20 / 110
 2500 ms 6548 KB 
#include <stdio.h>

#define N	200000
#define INF	0x3f3f3f3f

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

long long ans;

void solve_batch(int *aa, int *bb, int *ll, int *rr, int *jj, int cnt) {
	int h, i, j;

	for (h = 0; h < cnt; h++) {
		j = jj[h];
		for (i = ll[j]; i < rr[j]; i++)
			ans = max(ans, (long long) aa[i] * bb[j] * (j - i + 1));
	}
}

void solve(int *aa, int *bb, int l, int r) {
	static int qqa[N], qqb[N], ppa[N], ppb[N], iia[N], iib[N], jj[N];
	int m = (l + r) / 2, i, j, cnt;

	if (r - l == 1) {
		ans = max(ans, (long long) aa[l] * bb[l]);
		return;
	}
	solve(aa, bb, l, m), solve(aa, bb, m, r);
	for (i = m - 1; i >= l; i--)
		qqa[i] = min(i + 1 == m ? INF : qqa[i + 1], aa[i]);
	for (i = m - 1; i >= l; i--)
		qqb[i] = min(i + 1 == m ? INF : qqb[i + 1], bb[i]);
	for (j = m; j < r; j++)
		ppa[j] = min(j == m ? INF : ppa[j - 1], aa[j]);
	for (j = m; j < r; j++)
		ppb[j] = min(j == m ? INF : ppb[j - 1], bb[j]);
	for (i = l, j = r - 1; i < m; i++) {
		while (j >= m && (qqa[i] > ppa[j] || qqb[i] > ppb[j]))
			j--;
		if (j >= m)
			ans = max(ans, (long long) qqa[i] * qqb[i] * (j - i + 1));
	}
	for (i = l, j = r - 1; j >= m; j--) {
		while (i < m && ppa[j] > qqa[i])
			i++;
		iia[j] = i;
	}
	for (i = l, j = r - 1; j >= m; j--) {
		while (i < m && ppb[j] > qqb[i])
			i++;
		iib[j] = i;
	}
	for (j = r - 1; j >= m; j--) {
		i = max(iia[j], iib[j]);
		if (i < m)
			ans = max(ans, (long long) ppa[j] * ppb[j] * (j - i + 1));
	}
	cnt = 0;
	for (j = r - 1; j >= m; j--)
		if (iia[j] < iib[j]) {
			if (cnt > 0 && iib[jj[cnt - 1]] < iia[j])
				solve_batch(qqb, ppa, iia, iib, jj, cnt), cnt = 0;
			jj[cnt++] = j;
		}
	if (cnt > 0)
		solve_batch(qqb, ppa, iia, iib, jj, cnt), cnt = 0;
	cnt = 0;
	for (j = r - 1; j >= m; j--)
		if (iib[j] < iia[j]) {
			if (cnt > 0 && iia[jj[cnt - 1]] < iib[j])
				solve_batch(qqa, ppb, iib, iia, jj, cnt), cnt = 0;
			jj[cnt++] = j;
		}
	if (cnt > 0)
		solve_batch(qqa, ppb, iib, iia, jj, cnt), cnt = 0;
}

int main() {
	static int aa[N], bb[N];
	int n, i;

	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d%d", &aa[i], &bb[i]);
	ans = 0;
	solve(aa, bb, 0, n);
	printf("%lld\n", ans);
	return 0;
}

Compilation message

histogram.c: In function 'main':
histogram.c:83:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
histogram.c:85:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |   scanf("%d%d", &aa[i], &bb[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 4 ms 332 KB Output is correct
5 Correct 3 ms 332 KB Output is correct
6 Correct 3 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 4 ms 328 KB Output is correct
10 Correct 4 ms 332 KB Output is correct
11 Correct 0 ms 204 KB Output is correct
12 Correct 3 ms 332 KB Output is correct

Subtask #2
0 / 90.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 4 ms 332 KB Output is correct
5 Correct 3 ms 332 KB Output is correct
6 Correct 3 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 4 ms 328 KB Output is correct
10 Correct 4 ms 332 KB Output is correct
11 Correct 0 ms 204 KB Output is correct
12 Correct 3 ms 332 KB Output is correct
13 Execution timed out 2589 ms 6548 KB Time limit exceeded
14 Halted 0 ms 0 KB -