// 1691. Maximum Height by Stacking Cuboids #include "leetcode.h" /* * given 'n' cuboids where the dimensions of the i'th cuboid is 'cuboids[i] = * [width_i, length_i, height_i]' (0-indexed). choosee a subset of 'cuboids' and * place them on each other. you can place cuboid 'i' on cuboid 'j' if 'width_i * <= width_j', and similarily for length and height. you can rearrange any * cuboid's dimensions by rotating it to put it on another cuboid. return the * maximum height of the stacked 'cuboids'. */ int cmp_len(const void *a, const void *b) { int aa = *(int *)a, bb = *(int *)b; return aa > bb ? 1 : -1; } int cmp_box(const void *a, const void *b) { int *aa = *(int **)a, *bb = *(int **)b; if (aa[2] > bb[2]) return 1; if (aa[2] < bb[2]) return -1; else { if (aa[1] > bb[1]) return 1; if (aa[1] < bb[1]) return -1; else { if (aa[0] > bb[0]) return 1; if (aa[0] < bb[0]) return -1; else return 0; } } } bool check(int *bottom, int *top) { return top[2] <= bottom[2] && top[1] <= bottom[1] && top[0] <= bottom[0] ? false : true; } int maxHeight(int **cuboids, int cuboidsSize, int *cuboidsColSize) { for (int i = 0; i < cuboidsSize; i++) qsort(cuboids[i], 3, sizeof(int), cmp_len); qsort(cuboids, cuboidsSize, sizeof(cuboids[0]), cmp_box); int *arr = (int *)malloc(cuboidsSize * sizeof(int)), max = arr[0]; for (int i = 1; i < cuboidsSize; i++) { for (int j = 0; j < i; j++) if (check(cuboids[i], cuboids[j])) arr[i] = fmax(arr[i], arr[j] + cuboids[i][2]); max = fmax(max, arr[i]); } free(arr); return max; } int main() { int c1i[3][3] = {{50, 45, 20}, {95, 37, 53}, {45, 23, 12}}, c2i[2][3] = {{38, 25, 45}, {76, 35, 3}}, c3i[6][3] = {{7, 11, 17}, {7, 17, 11}, {11, 7, 17}, {11, 17, 7}, {17, 7, 11}, {17, 11, 7}}; struct two_d_arr c1, c2, c3; two_d_arr_init(&c1, 3, 3, c1i); two_d_arr_init(&c2, 2, 3, c2i); two_d_arr_init(&c3, 6, 3, c3i); printf("%d\n", maxHeight(c1.arr, c1.row_size, c1.col_size)); // expect: 190 printf("%d\n", maxHeight(c2.arr, c2.row_size, c2.col_size)); // expect: 76 printf("%d\n", maxHeight(c3.arr, c3.row_size, c3.col_size)); // expect: 102 two_d_arr_free(&c1), two_d_arr_free(&c2), two_d_arr_free(&c3); }