// 2300. Successful Pairs of Spells and Potions #include #include /* * given two positive integer arrays 'spells' and 'potions', of length n and m * respectively where 'spells[i]' represents the strength of the i'th spell and * 'potions[j] represents the strength of the j'th potion. also given an integer * success. a spell and potion pair is considered successful if the product of * their strengths is at least 'success'. return an integer array 'pairs' of * lengthn where 'pairs[i]' is the number of potions that will form a successful * pair with the i'th spell. */ int cmp(const void *a, const void *b) { return *(int *)a - *(int *)b; } int find_successful(int *potions, int potions_size, double val) { int left = 0, right = potions_size - 1, mid; while (left < right) { mid = (left + right) >> 1; if ((double)potions[mid] >= val) right = mid; else left = mid + 1; } if ((double)potions[left] >= val) return potions_size - left; else return 0; } int *successfulPairs(int *spells, int spells_size, int *potions, int potions_size, long long success, int *return_size) { int i, j; qsort(potions, potions_size, sizeof(int), cmp); double *spells_float = malloc(spells_size * sizeof(double)); for (i = 0; i < spells_size; i++) spells_float[i] = 1.0 * success / spells[i]; *return_size = spells_size; int *ans = malloc(spells_size * sizeof(int)); for (i = 0; i < spells_size; i++) ans[i] = find_successful(potions, potions_size, spells_float[i]); free(spells_float); return ans; } int main() { int s1[] = {5, 1, 3}, s2[] = {3, 1, 2}; int p1[] = {1, 2, 3, 4, 5}, p2[] = {8, 5, 8}; int rs1[] = {3}, rs2[] = {3}; int *ex1 = successfulPairs(s1, 3, p1, 5, 7, rs1); int *ex2 = successfulPairs(s2, 3, p2, 3, 16, rs2); for (int i = 0; i < 3; i++) printf("%d ", ex1[i]); // expect: 4 0 3 printf("\n"); for (int i = 0; i < 3; i++) printf("%d ", ex2[i]); // expect: 2 0 2 }