// 2491. Divide Players Into Teams of Equal Skill #include "leetcode.h" /* * you are given a positive integer array 'skill' of even length 'n' where * 'skill[i]' denotes the skill of the i'th player. divide the players into 'n / * 2' teams of size '2' such that the total skill of each team is equal. the * chemistry of team is equal to the product of the skills of the players on * that team. return the sum of the chemistry of all the teams, or return -1 if * there is no way to divide the players into teams such that the total skill of * each team is equal */ int cmp(const void *a, const void *b) { return *((int *)a) - *((int *)b); } long long dividePlayers(int *skill, int skillSize) { long long ans = 0, team; qsort(skill, skillSize, sizeof(int), cmp); team = skill[0] + skill[skillSize - 1]; for (int i = 0, j = skillSize - 1; i < j; i++, j--) { if (skill[i] + skill[j] != team) return -1; else ans += skill[i] * skill[j]; } return ans; } int main() { int s1[] = {3, 2, 5, 1, 3, 4}, s2[] = {3, 4}, s3[] = {1, 1, 2, 3}; printf("%lld\n", dividePlayers(s1, ARRAY_SIZE(s1))); // expect: 22 printf("%lld\n", dividePlayers(s2, ARRAY_SIZE(s2))); // expect: 12 printf("%lld\n", dividePlayers(s3, ARRAY_SIZE(s3))); // expect: -1 }