// 1219. Path with Maximum Gold #include "leetcode.h" /* * in a gold mine 'grid' of size 'm * n' each cell in this mine has an integer * representing the amount of gold in that cell, 0 if it is empty. return the * maximum amount of gold you can collect under the conditions: every time you * are located in a cell, you will collect all the gold in that cell. from your * position, you can walk one step to the left, right, up, or down. you cannot * visit thesame cell more than once. never visit a cell with 0 gold. you can * start and stop collecting gold from any position in the grid that has some * gold. */ void dfs(int **grid, int m, int n, int i, int j, int val, int *ans) { if (i < 0 || j < 0 || i == m || j == n || !grid[i][j]) { *ans = fmax(*ans, val); return; } int start_pos = grid[i][j]; grid[i][j] = 0; dfs(grid, m, n, i + 1, j, val + start_pos, ans); dfs(grid, m, n, i - 1, j, val + start_pos, ans); dfs(grid, m, n, i, j + 1, val + start_pos, ans); dfs(grid, m, n, i, j - 1, val + start_pos, ans); grid[i][j] = start_pos; } int getMaximumGold(int **grid, int gridSize, int *gridColSize) { int ans = 0, m = gridSize, n = *gridColSize; for (int i = 0; i < m; i++) for (int j = 0; j < n; j++) { if (!grid[i][j]) continue; dfs(grid, m, n, i, j, 0, &ans); } return ans; }