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Diffstat (limited to 'max_num_k_div_comp.c')
-rw-r--r-- | max_num_k_div_comp.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/max_num_k_div_comp.c b/max_num_k_div_comp.c new file mode 100644 index 0000000..c57b983 --- /dev/null +++ b/max_num_k_div_comp.c @@ -0,0 +1,73 @@ +// 2872. Maximum Number of K-Divisible Components +#include "leetcode.h" + +/* + * there is an undirected tree with 'n' nodes labeled from 0 to 'n - 1'. you are + * given the integer 'n' and a 2d integer array 'edges' of length 'n - 1', where + * 'edges[i] = [a_i, b_i]' indicates that there is an edge between nodes 'a_i' + * and 'b_i' in the tree. you are also given a 0-indexed integer array 'values' + * of length 'n' where 'values[i]' is the value associated with the i'th node + * and an integer 'k'. a valid split of the tree is obtained by removing any set + * of edges, possibly empty, from the tree such that the resulting components + * all have values thatare divisible by 'k', where the value of a connected + * component is the sum of the values of its node. return the maximum number of + * components in any valid split + */ + +struct vec { + int *arr; + int size; +}; + +void push(struct vec *a, int val) { + a->arr = (int *)realloc(a->arr, (a->size + 1) * sizeof(int)); + a->arr[a->size] = val; + ++a->size; +} + +int dfs(int node, int parent, struct vec *adj, int *vals, int k, int *matches, + int n) { + int sum = 0, neighbour = adj[node].size; + for (int i = 0; i < neighbour; ++i) { + int n_node = adj[node].arr[i]; + if (n_node == parent) + continue; + sum += dfs(n_node, node, adj, vals, k, matches, n); + } + sum += vals[node]; + sum %= k; + if (!sum) + ++(*matches); + return sum; +} + +int maxKDivisibleComponents(int n, int **edges, int edgesSize, + int *edgesColSize, int *values, int valuesSize, + int k) { + struct vec *adj = (struct vec *)malloc(n * sizeof(struct vec)); + for (int i = 0; i < n; ++i) + adj[i] = (struct vec){(int *)malloc(0 * sizeof(int)), 0}; + for (; edgesSize; ++edges, --edgesSize) { + int first = (*edges)[0], second = (*edges)[1]; + push(adj + first, second); + push(adj + second, first); + } + int matches = 0; + dfs(0, -1, adj, values, k, &matches, n); + return matches; +} + +int main() { + int e1i[4][2] = {{0, 2}, {1, 2}, {1, 3}, {2, 4}}, v1[] = {1, 8, 1, 4, 4}; + int e2i[6][2] = {{0, 1}, {0, 2}, {1, 3}, {1, 4}, {2, 5}, {2, 6}}, + v2[] = {3, 0, 6, 1, 5, 2, 1}; + struct two_d_arr e1, e2; + two_d_arr_init(&e1, 4, 2, e1i); + two_d_arr_init(&e2, 6, 2, e2i); + printf("%d\n", maxKDivisibleComponents(5, e1.arr, e1.row_size, e1.col_size, + v1, ARRAY_SIZE(v1), 6)); // expect: 2 + printf("%d\n", maxKDivisibleComponents(7, e2.arr, e2.row_size, e2.col_size, + v2, ARRAY_SIZE(v2), 3)); // expect: 2 + two_d_arr_free(&e1); + two_d_arr_free(&e2); +} |