Submission #1068881

#	Time	Username	Problem	Language	Result	Execution time	Memory
1068881		sleepntsheep	Wombats (IOI13_wombats)	C++17	28 / 100	4747 ms	108624 KiB

wombats

#pragma GCC optimize("O3,unroll-loops")
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
using namespace std;

#include "wombats.h"

#ifndef ROW
#define ROW 5000
#endif

#define COL 200

/* 256 Mb memory - 64 Million Ints
 - one matrix is 200x200 -> max 1600
 block + segtree
Memory - 200^2 * 2 * ceil(5000 / B)
Time Per update - [ 200 * 200 * B + lg[ceil(5000 / B)] * 200 * 200]
	there are 500 updates
Time for Init - [ 200 * 200 * B * ceil(5000 / B) + 200 * 200 * ceil(5000 / B) ]
		= [ 200 * 200 * 5000 + 200 * 200 * ceil(5000 / B) ]
1600 matrix - maybe B = 8, [5000 / B] = 625
*/

constexpr int B = 8;
int nb;

int r, c, h[5009][COL], v[5009][COL];

int L[9999], R[9999], a[1300][COL][COL];

void Unit(int blk) {
	for (int ii = 0; ii < c; ++ii) {
		static int dp[2][COL];
		/* find answer for (V1, V2) where V1 = ii */
		memset(dp[0], 63, sizeof dp[0]);
		dp[0][ii] = 0;
		int I = 0;
		for (int i = L[blk]; i <= R[blk]; ++i, I ^= 1) {
			if (i < r) {
				int pre = 1e9, suf = 1e9;
				for (int j = 0; j < c; ++j) {
					pre = min(pre, dp[I][j] - h[i][j]);
					dp[I][j] = min(dp[I][j], h[i][j] + pre);
				}
				for (int j = c - 1; j >= 0; --j) {
					suf = min(suf, dp[I][j] + h[i][j]);
					dp[I][j] = min(dp[I][j], suf - h[i][j]);
				}
			}
			for (int j = 0; j < c; ++j) dp[!I][j] = dp[I][j] + v[i][j];
		}
		for (int jj = 0; jj < c; ++jj)
			a[blk + nb][ii][jj] = dp[I][jj];
	}
}

void merg(int v) {
	for (int i = 0; i < c; ++i) for (int j = 0; j < c; ++j) a[v][i][j] = 1e9;
	for (int i = 0; i < c; ++i) for (int j = 0; j < c; ++j)
		for (int k = 0; k < c; ++k)
			a[v][i][j] = min(a[v][i][j], a[2 * v][i][k] + a[2 * v + 1][k][j]);
}

void init(int R, int C, int H[ROW][200], int V[ROW][200]) {
	r = R, c = C;
	for (int i = 0; i + 1 < r; ++i) for (int j = 0; j < c; ++j) v[i][j] = V[i][j];
	for (int i = 0 ; i < r; ++i) for (int j = 0; j + 1 < c; ++j) h[i][j + 1] = H[i][j] + h[i][j];

	nb = (r + B - 1) / B;
	while ((nb - 1) & nb) ++nb;

    	for (int i = 0; i < nb; ++i) {
    		L[i] = i * B;
    		::R[i] = min(r - 1, i * B + B - 1);
		Unit(i);
    	}
	for (int i = nb; --i; ) merg(i);
}

void update(int p) {
	Unit(p);
	for (p += nb; p /= 2; ) merg(p);
}

void changeH(int P, int Q, int W) {
	int dl = W - h[P][Q + 1] + h[P][Q];
	for (int j = Q + 1; j < c; ++j) h[P][j] += dl;
	update(P / B);
}

void changeV(int P, int Q, int W) {
	v[P][Q] = W;
	update(P / B);
}

int escape(int V1, int V2) { return a[1][V1][V2]; }

Compilation message (stderr)

grader.c: In function 'int main()':
grader.c:15:6: warning: variable 'res' set but not used [-Wunused-but-set-variable]
   15 |  int res;
      |      ^~~

• Subtask 1: 0 / 9
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 0 / 18
• Subtask 5: 0 / 21
• Subtask 6: 0 / 24