carloscn
commented
11 months ago Analysis
static int32_t number_of_pairs(int32_t *nums, size_t nums_size, int32_t *out, size_t *o_len)
{
int32_t ret = 0;
STACK_T *stack = NULL;
UTILS_CHECK_LEN(nums_size);
UTILS_CHECK_PTR(nums);
UTILS_CHECK_PTR(out);
UTILS_CHECK_PTR(o_len);
stack = stack_malloc(STACK_DEFAULT_SIZE);
UTILS_CHECK_PTR(stack);
ret = utils_sort_int32_array(nums, nums_size, ORDER_BY_ASCEND);
UTILS_CHECK_RET(ret);
for (size_t i = 0; i < nums_size; i ++) {
if (stack_get_top(stack) == 0) {
ret = stack_push(stack, nums[i]);
UTILS_CHECK_RET(ret);
continue;
}
int64_t e = 0;
ret = stack_peek(stack, &e);
UTILS_CHECK_RET(ret);
ret = ((int32_t)e == nums[i]) ?
stack_pop(stack, NULL):
stack_push(stack, nums[i]);
UTILS_CHECK_RET(ret);
}
*o_len = 0;
size_t deleted_pair_len = (nums_size - stack_get_top(stack)) / 2;
*(out) = (int32_t) deleted_pair_len, (*o_len) ++;
*(out + 1) = (int32_t) stack_get_top(stack), (*o_len) ++;
finish:
stack_free(stack);
return ret;
}
Description
You are given a 0-indexed integer array nums. In one operation, you may do the following:
Choose two integers in nums that are equal. Remove both integers from nums, forming a pair. The operation is done on nums as many times as possible.
Return a 0-indexed integer array answer of size 2 where answer[0] is the number of pairs that are formed and answer[1] is the number of leftover integers in nums after doing the operation as many times as possible.
Example 1:
Input: nums = [1,3,2,1,3,2,2] Output: [3,1] Explanation: Form a pair with nums[0] and nums[3] and remove them from nums. Now, nums = [3,2,3,2,2]. Form a pair with nums[0] and nums[2] and remove them from nums. Now, nums = [2,2,2]. Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = [2]. No more pairs can be formed. A total of 3 pairs have been formed, and there is 1 number leftover in nums.
Example 2:
Input: nums = [1,1] Output: [1,0] Explanation: Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = []. No more pairs can be formed. A total of 1 pair has been formed, and there are 0 numbers leftover in nums. Example 3:
Input: nums = [0] Output: [0,1] Explanation: No pairs can be formed, and there is 1 number leftover in nums.
Constraints:
1 <= nums.length <= 100 0 <= nums[i] <= 100