#P11000. Count Valid Numeric Strings
Count Valid Numeric Strings
Count Valid Numeric Strings
Little Blue wants to construct a numeric string of length 10000 with the following conditions:
- The digit
0
is not allowed (only digits 1 through 9 are permitted). - The string must contain the digits
3
and7
at least once.
Determine the total number of valid numeric strings that satisfy these requirements. Since the answer can be very large, output it modulo \(10^9+7\).
inputFormat
This problem does not use any input. The length of the numeric string is fixed at 10000
.
outputFormat
Output a single integer representing the number of valid numeric strings modulo \(10^9+7\).
sample
228155372