// 2967. Minimum Cost to Make Array Equalindromic #include "leetcode.h" /* * you are given a 0-indexed integer array 'nums' having length 'n'. you are * allowed to perform a special move any number of times on 'nums'. in one * special move, you perform the following steps in order: choose an index 'i' * in the range '[0, n - 1]' and a positive integer 'x', add '|nums[i] - x|' to * the total cost, and change the value of 'nums[i]' to 'x'. a palindromic * number is a positive integer that remains the same when its digits are * reversed. an array is considered equalindromic if all the elements in the * array are equal to an integer 'y', where 'y' is a palindromic number less * than 10^9. return an integer denoting the minimum possible total cost to make * 'nums' equalindromic by performing any number of special moves */ bool is_palindrome(int num) { if (num < 0) return false; int reverse = 0, original = num; while (num) { int digit = num % 10; if (reverse > (INT_MAX - digit) / 10) return false; reverse = reverse * 10 + digit; num /= 10; } return reverse == original; } long long calculate_cost(int *nums, int numsSize, int target) { long long cost = 0; for (int i = 0; i < numsSize; i++) cost += abs(nums[i] - target); return cost; } int cmp(const void *a, const void *b) { return (*(int *)a - *(int *)b); } long long minimumCost(int *nums, int numsSize) { qsort(nums, numsSize, sizeof(int), cmp); int median = nums[numsSize / 2]; int lower = median - 100000, upper = median + 100000; if (lower < 1) lower = 1; if (upper > 1000000000) upper = 1000000000; long long min_cost = LLONG_MAX; for (int i = 0; i <= upper; i++) if (is_palindrome(i)) { long long curr_cost = calculate_cost(nums, numsSize, i); if (curr_cost < min_cost) min_cost = curr_cost; } return min_cost; } int main() { int n1[] = {1, 2, 3, 4, 5}, n2[] = {10, 12, 13, 14, 15}, n3[] = {22, 33, 22, 33, 22}; printf("%lld\n", minimumCost(n1, ARRAY_SIZE(n1))); // expect: 6 printf("%lld\n", minimumCost(n2, ARRAY_SIZE(n2))); // expect: 11 printf("%lld\n", minimumCost(n3, ARRAY_SIZE(n3))); // expect: 22 }