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// 2684. Maximum Number of Moves in a Grid
#include "leetcode.h"
/*
* given a 0-indexed array 'm * n' grid consisting of positive integers. you can
* start at any cell in the first column of the matrix and traverse the grid in
* the following way: from cell '(row, col)', you can move to any of the cells:
* '(row - 1, col + 1), (row, col + 1), and (row + 1, col + 1)'. such that thhe
* value of the cell you are moving to should be strictly bigger than the value
* of the current cell. return the maximum number of moves that you can perform.
*/
// int dfs(int **dp, int **grid, int row_size, int *col_size, int row, int col,
// int prev, int ith) {
int dfs(int **dp, int r, int c, int grid[r][c], int row_size, int *col_size,
int row, int col, int prev, int ith) {
if (row < 0 || row >= row_size || col < 0 || col > *col_size - 1 ||
grid[row][col] <= prev)
return ith;
if (dp[row][col])
return ith + dp[row][col] + 1;
int tmp = dfs(dp, r, c, grid, row_size, col_size, row - 1, col + 1,
grid[row][col], ith + 1);
tmp = fmax(tmp, dfs(dp, r, c, grid, row_size, col_size, row, col + 1,
grid[row][col], ith + 1));
tmp = fmax(tmp, dfs(dp, r, c, grid, row_size, col_size, row + 1, col,
grid[row][col], ith + 1));
dp[row][col] = tmp - ith - 1;
return tmp;
}
// int maxMoves(int **grid, int grid_size, int *grid_col_size) {
int maxMoves(int r, int c, int grid[r][c], int grid_size, int *grid_col_size) {
int ans = 0;
int **dp = malloc(sizeof(int *) * grid_size);
for (int i = 0; i < grid_size; i++)
dp[i] = calloc(*grid_col_size, sizeof(int));
for (int i = 0; i < grid_size; i++)
ans = fmax(ans, dfs(dp, r, c, grid, grid_size, grid_col_size, i, 0, 0, -1));
return ans;
}
int main() {
int g1[4][4] = {{2, 4, 3, 5}, {5, 4, 9, 3}, {3, 4, 2, 11}, {10, 9, 13, 15}};
int g2[3][3] = {{3, 2, 4}, {2, 1, 9}, {1, 1, 7}};
int gcs1[] = {}, gcs2[] = {};
printf("%d\n", maxMoves(4, 4, g1, 4, gcs1)); // expect: 3
printf("%d\n", maxMoves(3, 3, g2, 3, gcs2)); // expect: 0
}
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