oj.uz

Submission #434146

# Submission time Handle Problem Language Result Execution time Memory
434146 2021-06-20T15:43:20 Z rainboy Salesman (IOI09_salesman) C
100 / 100
 542 ms 36552 KB 
#include <stdio.h>

#define N	500000
#define X	500001
#define INF	0x3f3f3f3f3f3f3f3f

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

unsigned int Z = 12345;

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

int tt[N], xx[N], yy[N];

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) {
			int c = tt[ii[j]] != tt[i_] ? tt[ii[j]] - tt[i_] : xx[ii[j]] - xx[i_];

			if (c == 0)
				j++;
			else if (c < 0) {
				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;
	}
}

void update(long long *ft, int i, long long x) {
	while (i <= X) {
		ft[i] = max(ft[i], x);
		i |= i + 1;
	}
}

long long query(long long *ft, int i) {
	long long x = -INF;

	while (i >= 0) {
		x = max(x, ft[i]);
		i &= i + 1, i--;
	}
	return x;
}

int main() {
	static long long ft1[X + 1], ft2[X + 1];
	static int ii[N];
	static long long dp[N], dq[N], dr[N];
	int n, u, d, s, h, i, j;

	scanf("%d%d%d%d", &n, &u, &d, &s);
	for (i = 0; i < n; i++) {
		scanf("%d%d%d", &tt[i], &xx[i], &yy[i]);
		ii[i] = i;
	}
	sort(ii, 0, n);
	for (i = 0; i <= X; i++)
		ft1[i] = ft2[i] = -INF;
	update(ft1, s, s * d), update(ft2, X - s, -s * u);
	for (i = 0; i < n; i = j) {
		int t = tt[ii[i]], x;

		j = i + 1;
		while (j < n && tt[ii[j]] == t)
			j++;
		for (h = i; h < j; h++) {
			x = xx[ii[h]];
			dr[h] = max(query(ft1, x) - x * d, query(ft2, X - x) + x * u);
		}
		for (h = i; h < j; h++) {
			dp[h] = dr[h];
			if (h > i)
				dp[h] = max(dp[h], dp[h - 1] - (xx[ii[h]] - xx[ii[h - 1]]) * d);
			dp[h] += yy[ii[h]];
		}
		for (h = j - 1; h >= i; h--) {
			dq[h] = dr[h];
			if (h + 1 < j)
				dq[h] = max(dq[h], dq[h + 1] - (xx[ii[h + 1]] - xx[ii[h]]) * u);
			dq[h] += yy[ii[h]];
		}
		for (h = i; h < j; h++)
			dr[h] = max(dp[h], dq[h]);
		for (h = i + 1; h < j; h++)
			dr[h] = max(dr[h], dr[h - 1] - (xx[ii[h]] - xx[ii[h - 1]]) * d);
		for (h = j - 2; h >= i; h--)
			dr[h] = max(dr[h], dr[h + 1] - (xx[ii[h + 1]] - xx[ii[h]]) * u);
		for (h = i; h < j; h++) {
			x = xx[ii[h]];
			update(ft1, x, dr[h] + x * d), update(ft2, X - x, dr[h] - x * u);
		}
	}
	printf("%lld\n", max(query(ft1, s) - s * d, query(ft2, X - s) + s * u));
	return 0;
}

Compilation message

salesman.c: In function 'main':
salesman.c:62:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |  scanf("%d%d%d%d", &n, &u, &d, &s);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
salesman.c:64:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |   scanf("%d%d%d", &tt[i], &xx[i], &yy[i]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 8140 KB Output is correct
2 Correct 4 ms 8140 KB Output is correct
3 Correct 5 ms 8140 KB Output is correct
4 Correct 6 ms 8236 KB Output is correct
5 Correct 10 ms 8320 KB Output is correct
6 Correct 20 ms 9292 KB Output is correct
7 Correct 46 ms 10952 KB Output is correct
8 Correct 95 ms 13824 KB Output is correct
9 Correct 148 ms 16256 KB Output is correct
10 Correct 275 ms 24464 KB Output is correct
11 Correct 332 ms 25172 KB Output is correct
12 Correct 426 ms 29848 KB Output is correct
13 Correct 463 ms 30096 KB Output is correct
14 Correct 542 ms 36552 KB Output is correct
15 Correct 519 ms 35656 KB Output is correct
16 Correct 516 ms 35668 KB Output is correct
17 Correct 5 ms 8140 KB Output is correct
18 Correct 4 ms 8140 KB Output is correct
19 Correct 6 ms 8140 KB Output is correct
20 Correct 6 ms 8280 KB Output is correct
21 Correct 6 ms 8268 KB Output is correct
22 Correct 7 ms 8396 KB Output is correct
23 Correct 8 ms 8396 KB Output is correct
24 Correct 8 ms 8396 KB Output is correct
25 Correct 86 ms 13344 KB Output is correct
26 Correct 200 ms 18636 KB Output is correct
27 Correct 343 ms 26276 KB Output is correct
28 Correct 333 ms 27116 KB Output is correct
29 Correct 453 ms 34188 KB Output is correct
30 Correct 462 ms 34960 KB Output is correct