#include <stdio.h> #include <stdint.h> #include <inttypes.h> static const unsigned LIMIT = 19 * 9 * 9; unsigned digits_squares_sum(uint64_t num) { unsigned result = 0; while(num) { unsigned digit = (unsigned) (num % 10); result += digit * digit; num /= 10; } return result; } int main() { uint64_t k, a, b; (void) scanf("%" SCNu64 "%" SCNu64 "%" SCNu64, &k, &a, &b); unsigned count = 0, mul; for(mul = 1; mul <= LIMIT && k * mul <= b; ++mul) { if(digits_squares_sum(k * mul) == mul && a <= k * mul) { ++count; } } printf("%u\n", count); return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | #include <stdio.h> #include <stdint.h> #include <inttypes.h> static const unsigned LIMIT = 19 * 9 * 9; unsigned digits_squares_sum(uint64_t num) { unsigned result = 0; while(num) { unsigned digit = (unsigned) (num % 10); result += digit * digit; num /= 10; } return result; } int main() { uint64_t k, a, b; (void) scanf("%" SCNu64 "%" SCNu64 "%" SCNu64, &k, &a, &b); unsigned count = 0, mul; for(mul = 1; mul <= LIMIT && k * mul <= b; ++mul) { if(digits_squares_sum(k * mul) == mul && a <= k * mul) { ++count; } } printf("%u\n", count); return 0; } |