diff options
Diffstat (limited to 'add_arr_form_int.c')
-rw-r--r-- | add_arr_form_int.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/add_arr_form_int.c b/add_arr_form_int.c new file mode 100644 index 0000000..2cadd67 --- /dev/null +++ b/add_arr_form_int.c @@ -0,0 +1,42 @@ +// 989. Add to Array-Form of Integer +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/* + * the array-form of an integer 'num' is an array representing its digits in + * left to right order. eg 'num = 1231', the array form is 1,3,2,1. given 'num', + * the array form of an integer, and an integer 'k', return the array-form of + * 'num + k' + */ + +int *addToArrayForm(int *num, int numSize, int k, int *returnSize) { + int *k_arr, *ans, k_size, r_size, p; + for (int i = k, k_size = 0; i > 0; i /= 10) + k_size++; + k_arr = malloc(sizeof(int) * k_size); + for (int i = k_size - 1, p = k; i >= 0; p /= 10) + k_arr[i--] = p % 10; + r_size = k_size > numSize ? k_size : numSize; + ans = malloc(sizeof(int) * (++r_size)); + for (int i = numSize, j = k_size, c = 0, p = r_size - 1; p >= 0; p--) { + c += i > 0 ? num[--i] : 0; + c += j > 0 ? k_arr[--j] : 0; + ans[p] = c % 10; + c /= 10; + } + if (ans[0] == 0) + memmove(ans, ans + 1, sizeof(int) * (--r_size)); + *returnSize = r_size; + free(k_arr); + return ans; +} + +int main() { + int num1[] = {1, 2, 0, 0}, ns1 = 4, k1 = 34, rs1[] = {4}; + int num2[] = {2, 7, 4}, ns2 = 3, k2 = 181, rs2[] = {3}; + int num3[] = {2, 1, 4}, ns3 = 3, k3 = 806, rs3[] = {4}; + printf("%d\n" * addToArrayForm(num1, ns1, k1, rs1)); + printf("%d\n" * addToArrayForm(num2, ns2, k2, rs2)); + printf("%d\n" * addToArrayForm(num3, ns3, k3, rs3)); +} |