diff options
Diffstat (limited to 'restore_array.c')
-rw-r--r-- | restore_array.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/restore_array.c b/restore_array.c new file mode 100644 index 0000000..16efddc --- /dev/null +++ b/restore_array.c @@ -0,0 +1,41 @@ +// 1416. Restore The Array +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/* + * a progamme was supposed to print an array of integers. the programme forgot + * to print whitespace and the array is printing as a string of digits 's' and + * all we know is that all integers in the array were in the range [1, k] and + * there are no leading zeros in the array. given the string 's' and the integer + * 'k', return the number of possible arrays that can be printed as 's' using + * the mentioned programme. return modulo 10^9+7 + */ + +int numberOfArrays(char *s, int k) { + const int mod = 1e9 + 7; + int n = strlen(s); + int *dp = calloc(n + 1, sizeof(int)); + dp[n] = 1; + for (int i = n - 1; i >= 0; i--) { + if (s[i] == '0') + continue; + long long num = 0; + for (int j = i; j < n; j++) { + num = num * 10 + s[j] - '0'; + if (num > k) + break; + dp[i] = (dp[i] + dp[j + 1]) % mod; + } + } + int ans = dp[0]; + free(dp); + return ans; +} + +int main() { + char s1_2[] = {"1000"}, s3[] = {"1317"}; + printf("%d\n", numberOfArrays(s1_2, 10000)); // expect: 1 + printf("%d\n", numberOfArrays(s1_2, 10)); // expect: 0 + printf("%d\n", numberOfArrays(s3, 2000)); // expect: 8 +} |