diff options
Diffstat (limited to 'find_k_closest_elements.c')
-rw-r--r-- | find_k_closest_elements.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/find_k_closest_elements.c b/find_k_closest_elements.c new file mode 100644 index 0000000..4a8e217 --- /dev/null +++ b/find_k_closest_elements.c @@ -0,0 +1,38 @@ +// 658. Find K Closest Elements +#include "leetcode.h" + +/* + * given a sorted integer array 'arr', two integers 'k' and 'x', return the 'k' + * closest integers to 'x' in the array. the result should also be sorted in + * ascending order. an integer 'a' is closer to 'x' than an integer 'b' if '|a - + * x| < |b - x|' or '|a - x| == |b - x|' and 'a < b'. + */ + +int *findClosestElements(int *arr, int arrSize, int k, int x, int *returnSize) { + int l = 0, r = arrSize - k; + while (l < r) { + int m = (l + r) / 2; + if (x - arr[m] > arr[m + k] - x) + l = m + 1; + else + r = m; + } + int *k_closest = (int *)calloc(k, sizeof(int)); + *returnSize = k; + for (int i = 0; i < k; i++) + k_closest[i] = arr[l++]; + return k_closest; +} + +int main() { + int a1[] = {1, 2, 3, 4, 5}, a2[] = {1, 2, 3, 4, 5}, rs1, rs2; + int *fce1 = findClosestElements(a1, ARRAY_SIZE(a1), 4, 3, &rs1); + int *fce2 = findClosestElements(a2, ARRAY_SIZE(a2), 4, -1, &rs2); + for (int i = 0; i < rs1; i++) + printf("%d ", fce1[i]); // expect: 1 2 3 4 + printf("\n"); + for (int i = 0; i < rs2; i++) + printf("%d ", fce2[i]); // expect: 1 2 3 4 + printf("\n"); + free(fce1), free(fce2); +} |