Submission #394551

#	Time	Username	Problem	Language	Result	Execution time	Memory
394551		rainboy	Teams (IOI15_teams)	C11	77 / 100	4059 ms	138280 KiB

teams

#include "teams.h"
#include <string.h>

#define N	500000
#define M	200000
#define LN	19	/* LN = ceil(log2(N)) */
#define N_	(N * (LN + 1))
#define INF	0x3f3f3f3f

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

unsigned int X = 12345;

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

int xx[N * 2], ii[N * 2], tt[N + 1], n;

int compare_x(int i, int j) { return xx[i] - xx[j]; }
int compare_k(int k1, int k2) { return k1 - k2; }

int (*compare)(int, int);

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 = compare(ii[j], 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;
	}
}

int ll[1 + N_], rr[1 + N_], sz[1 + N_], _ = 1;

int update(int t, int l, int r, int i) {
	int t_ = _++;

	sz[t_] = sz[t] + 1;
	if (r - l > 1) {
		int m = (l + r) / 2;

		if (i < m)
			ll[t_] = update(ll[t], l, m, i), rr[t_] = rr[t];
		else
			ll[t_] = ll[t], rr[t_] = update(rr[t], m, r, i);
	}
	return t_++;
}

int query(int t, int i) {
	int l = 0, r = n, x;

	x = 0;
	while (r - l > 1) {
		int m = (l + r) / 2;

		if (i < m)
			x += sz[rr[t]], t = ll[t], r = m;
		else
			t = rr[t], l = m;
	}
	if (i == -1)
		x += sz[t];
	return x;
}

void init(int n_, int ll[], int rr[]) {
	int h, i, t;

	n = n_;
	for (i = 0; i < n * 2; i++) {
		xx[i] = (i & 1) == 0 ? ll[i >> 1] : rr[i >> 1] + 1;
		ii[i] = i;
	}
	compare = compare_x, sort(ii, 0, n * 2);
	for (h = 0, i = 0, t = 0; i <= n; i++) {
		while (h < n * 2 && xx[ii[h]] - 1 == i) {
			if ((ii[h] & 1) == 1)
				t = update(t, 0, n, xx[ii[h] ^ 1] - 1);
			h++;
		}
		tt[i] = t;
	}
}

int iq[1 + N], pq[N], cnt;

int lt(int i, int j) { return xx[i << 1 | 1] < xx[j << 1 | 1]; }

int p2(int p) {
	return (p *= 2) > cnt ? 0 : (p < cnt && lt(iq[p + 1], iq[p]) ? p + 1 : p);
}

void pq_up(int i) {
	int p, q, j;

	for (p = pq[i]; (q = p / 2) && lt(i, j = iq[q]); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_dn(int i) {
	int p, q, j;

	for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_add(int i) {
	pq[i] = ++cnt, pq_up(i);
}

void pq_remove(int i) {
	if (pq[i]) {
		int j = iq[cnt--];

		if (j != i)
			pq[j] = pq[i], pq_up(j), pq_dn(j);
		pq[i] = 0;
	}
}

void pq_remove_first() {
	pq_remove(iq[1]);
}

int greedy(int *kk, int m) {
	int h, i;

	compare = compare_k, sort(kk, 0, m);
	memset(pq, 0, n * sizeof *pq), cnt = 0;
	for (h = 0, i = 0; h < m; h++) {
		while (i < n * 2 && xx[ii[i]] <= kk[h]) {
			int i_ = ii[i++];

			if ((i_ & 1) == 0)
				pq_add(i_ >> 1);
			else
				pq_remove(i_ >> 1);
		}
		if (cnt < kk[h])
			return 0;
		while (kk[h]--)
			pq_remove_first();
	}
	return 1;
}

int hall(int *kk, int m) {
	static int dp[M + 2];
	int i, j;

	dp[0] = n;
	for (j = 1; j <= m + 1; j++) {
		int r = j == m + 1 ? n : kk[j - 1] - 1;

		dp[j] = INF;
		for (i = 0; i < j; i++) {
			int l = i == 0 ? -1 : kk[i - 1] - 1;

			dp[j] = min(dp[j], dp[i] - query(tt[r], i == 0 ? -1 : kk[i - 1] - 1));
		}
		dp[j] -= j == m + 1 ? 0 : kk[j - 1];
	}
	return dp[m + 1] >= 0;
}

int can(int m, int kk[]) {
	int j;

	compare = compare_k, sort(kk, 0, m);
	return m >= 500 ? greedy(kk, m) : hall(kk, m);
}

Compilation message (stderr)

teams.c: In function 'rand_':
teams.c:15:18: warning: conversion to 'int' from 'unsigned int' may change the sign of the result [-Wsign-conversion]
   15 |  return (X *= 3) >> 1;
      |         ~~~~~~~~~^~~~
teams.c: In function 'sort':
teams.c:25:16: warning: declaration of 'ii' shadows a global declaration [-Wshadow]
   25 | void sort(int *ii, int l, int r) {
      |           ~~~~~^~
teams.c:18:16: note: shadowed declaration is here
   18 | int xx[N * 2], ii[N * 2], tt[N + 1], n;
      |                ^~
teams.c: In function 'init':
teams.c:81:23: warning: declaration of 'll' shadows a global declaration [-Wshadow]
   81 | void init(int n_, int ll[], int rr[]) {
      |                   ~~~~^~~~
teams.c:47:5: note: shadowed declaration is here
   47 | int ll[1 + N_], rr[1 + N_], sz[1 + N_], _ = 1;
      |     ^~
teams.c:81:33: warning: declaration of 'rr' shadows a global declaration [-Wshadow]
   81 | void init(int n_, int ll[], int rr[]) {
      |                             ~~~~^~~~
teams.c:47:17: note: shadowed declaration is here
   47 | int ll[1 + N_], rr[1 + N_], sz[1 + N_], _ = 1;
      |                 ^~
teams.c: In function 'greedy':
teams.c:146:18: warning: conversion to 'long unsigned int' from 'int' may change the sign of the result [-Wsign-conversion]
  146 |  memset(pq, 0, n * sizeof *pq), cnt = 0;
      |                  ^
teams.c: In function 'hall':
teams.c:174:8: warning: unused variable 'l' [-Wunused-variable]
  174 |    int l = i == 0 ? -1 : kk[i - 1] - 1;
      |        ^
teams.c: In function 'can':
teams.c:184:6: warning: unused variable 'j' [-Wunused-variable]
  184 |  int j;
      |      ^

• Subtask 1: 21 / 21
• Subtask 2: 13 / 13
• Subtask 3: 43 / 43
• Subtask 4: 0 / 23