Submission #9827

#	Time	Username	Problem	Language	Result	Execution time	Memory
9827		veckal	On grid (kriii2_O)	C++14	4 / 4	464 ms	107612 KiB

O

#include<stdio.h>
#include<string.h>

int r, c, grid[300][300], psum[300][300];
int cache[300][300], reCache[300][300][300];

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

int reverseGrid(int, int, int);

int onGrid(int y, int x) {
	int &ret = cache[y][x];
	if (~ret) return ret;
	ret = psum[y][x];
	if (!y || !x) return ret;
	for (int h=0; h<y; ++h)
		ret = max(ret, reverseGrid(y, x-1, h) + psum[y][x] - psum[h][x] - psum[y][x-1] + psum[h][x-1]);
	return ret;
}

int reverseGrid(int y, int x, int h) {
	int &ret = reCache[y][x][h];
	if (~ret) return ret;
	ret = onGrid(h, x);
	if (x == 0) return ret;
	int smallGrid = psum[y][x] - psum[h][x] - psum[y][x-1] + psum[h][x-1];
	ret = max(ret, reverseGrid(y, x-1, h) + smallGrid);
	ret = max(ret, onGrid(h, x-1) + smallGrid);
	return ret;
}

int main() {
	scanf("%d%d", &r, &c);
	for (int i=0; i<r; ++i)
		for (int j=0; j<c; ++j)
			scanf("%d", grid[i]+j);
	psum[0][0] = grid[0][0];
	for (int i=1; i<c; ++i)
		psum[0][i] = psum[0][i-1] + grid[0][i];
	for (int i=1; i<r; ++i) {
		psum[i][0] = grid[i][0] + psum[i-1][0];
		for (int j=1; j<c; ++j)
			psum[i][j] = psum[i][j-1] + psum[i-1][j] + grid[i][j] - psum[i-1][j-1];
	}
	memset(cache, -1, sizeof cache);
	memset(reCache, -1, sizeof reCache);
	printf("%d\n", onGrid(r-1, c-1));
	return 0;
}

• Subtask 1: 1 / 1
• Subtask 2: 3 / 3