diff options
Diffstat (limited to 'grid_game.c')
-rw-r--r-- | grid_game.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/grid_game.c b/grid_game.c new file mode 100644 index 0000000..1945c92 --- /dev/null +++ b/grid_game.c @@ -0,0 +1,45 @@ +// 2017. Grid Game +#include "leetcode.h" + +/* + * you are given a 0-indexed 2d array 'grid' of size '2 x n' where 'grid[r][c]' + * represents the number of points at position '[r, c]' on the matrix. two + * robots are playing a game on this matrix. both robots initially starts at + * '(0, 0)' and want to reach '(1, n - 1)'. each robot may only move to the + * right or down. at the start of the game, the first robot moves from '(0, 0)' + * to '(1, n - 1)', collecting all the points. first robot wants to minimise the + * number of points collected by the second robot. in contrast, the second robot + * wants to maximise the number of points it collects. return the number of + * points collected by the second robot + */ + +long long gridGame(int **grid, int gridSize, int *gridColSize) { + long long down = 0, up = 0; + for (int i = 0; i < gridColSize[0] - 1; i++) + down += grid[1][i]; + long long ans = down; + for (int i = gridColSize[0] - 1; i; i--) { + int cnt = fmax(down, up); + if (cnt < ans) + ans = cnt; + up += grid[0][i]; + down -= grid[1][i - 1]; + } + return up < ans ? up : ans; +} + +int main() { + int g1i[2][3] = {{2, 5, 4}, {1, 5, 1}}; + int g2i[2][3] = {{3, 3, 1}, {8, 5, 2}}; + int g3i[2][4] = {{1, 3, 1, 15}, {1, 3, 3, 1}}; + struct two_d_arr g1, g2, g3; + two_d_arr_init(&g1, ARRAY_SIZE(g1i), ARRAY_SIZE(g1i[0]), g1i); + two_d_arr_init(&g2, ARRAY_SIZE(g2i), ARRAY_SIZE(g2i[0]), g2i); + two_d_arr_init(&g3, ARRAY_SIZE(g3i), ARRAY_SIZE(g3i[0]), g3i); + printf("%lld\n", gridGame(g1.arr, g1.row_size, g1.col_size)); // expect: 4 + printf("%lld\n", gridGame(g2.arr, g2.row_size, g2.col_size)); // expect: 4 + printf("%lld\n", gridGame(g3.arr, g3.row_size, g3.col_size)); // expect: 7 + two_d_arr_free(&g1); + two_d_arr_free(&g2); + two_d_arr_free(&g3); +} |