// 1462. Course Schedule IV #include "leetcode.h" /* * there are a total of 'numCourses' courses that you have to take, labeled from * 0 to 'numCourses - 1'. you are given an array 'prerequisites' where * 'prerequisites[i] = [a_i, b_i]' indicates that you must take course 'a_i' * before 'b_i'. prerequisites can also be indirect. if course 'a' is a * prerequisite of course 'b', and course 'b' is a prerequisite of course 'c', * then course 'a' is a prerequisite of course 'c'. you are also given an array * 'queries' where 'queries[j] = [u_j, v_j]'. for the j'th query, you should * answer whether course 'u_j' is a prerequisite of course 'v_j' or not. */ bool *checkIfPrerequisite(int numCourses, int **prerequisites, int prerequisitesSize, int *prerequisitesColSize, int **queries, int queriesSize, int *queriesColSize, int *returnSize) { *returnSize = queriesSize; bool *ans = (bool *)malloc(queriesSize * sizeof(bool)); bool **connected = (bool **)malloc(numCourses * sizeof(bool *)); for (int i = 0; i < numCourses; i++) connected[i] = (bool *)calloc(numCourses, sizeof(bool)); for (int i = 0; i < prerequisitesSize; i++) { int a = prerequisites[i][0]; int b = prerequisites[i][1]; connected[a][b] = true; } for (int k = 0; k < numCourses; k++) for (int i = 0; i < numCourses; i++) for (int j = 0; j < numCourses; j++) if (connected[i][k] && connected[k][j]) connected[i][j] = true; for (int i = 0; i < queriesSize; i++) { int u = queries[i][0]; int v = queries[i][1]; ans[i] = connected[u][v]; } for (int i = 0; i < numCourses; i++) free(connected[i]); free(connected); return ans; } int main() { int p1i[1][2] = {{1, 0}}, q1i[2][2] = {{0, 1}, {1, 0}}, rs1; int p2i[1][0] = {{}}, q2i[2][2] = {{1, 0}, {0, 1}}, rs2; int p3i[3][2] = {{1, 2}, {1, 0}, {2, 0}}, q3i[2][2] = {{1, 0}, {1, 2}}, rs3; struct two_d_arr p1, q1, p2, q2, p3, q3; two_d_arr_init(&p1, ARRAY_SIZE(p1i), ARRAY_SIZE(p1i[0]), p1i); two_d_arr_init(&p2, 0, ARRAY_SIZE(p2i[0]), p2i); two_d_arr_init(&p3, ARRAY_SIZE(p3i), ARRAY_SIZE(p3i[0]), p3i); two_d_arr_init(&q1, ARRAY_SIZE(q1i), ARRAY_SIZE(q1i[0]), q1i); two_d_arr_init(&q2, ARRAY_SIZE(q2i), ARRAY_SIZE(q2i[0]), q2i); two_d_arr_init(&q3, ARRAY_SIZE(q3i), ARRAY_SIZE(q3i[0]), q3i); bool *cip1 = checkIfPrerequisite(2, p1.arr, p1.row_size, p1.col_size, q1.arr, q1.row_size, q1.col_size, &rs1); bool *cip2 = checkIfPrerequisite(2, p2.arr, p2.row_size, p2.col_size, q2.arr, q2.row_size, q2.col_size, &rs2); bool *cip3 = checkIfPrerequisite(3, p3.arr, p3.row_size, p3.col_size, q3.arr, q3.row_size, q3.col_size, &rs3); for (int i = 0; i < rs1; i++) printf("%d ", cip1[i]); // expect: 0 1 printf("\n"); for (int i = 0; i < rs2; i++) printf("%d ", cip2[i]); // expect: 0 0 printf("\n"); for (int i = 0; i < rs3; i++) printf("%d ", cip3[i]); // expect: 1 1 printf("\n"); free(cip1); free(cip2); free(cip3); two_d_arr_free(&p1); two_d_arr_free(&p2); two_d_arr_free(&p3); two_d_arr_free(&q1); two_d_arr_free(&q2); two_d_arr_free(&q3); }