#include <cstdio> int ord(unsigned long long n) { int tens = 0; while (n > 0) { tens++; n /= 10; } return tens; } int main() { unsigned long long a, b, k; unsigned long long sum = 0; unsigned long long max = 18 * 81; unsigned long long left, right; scanf("%llu %llu %llu", &k, &a, &b); left = right = b + 1; if ((k >= (a / max)) && (k <= b)) { if (k < a) { left = a - (a % k); if (a % k) { left += k; } } else { left = k; } if (ord(left) + ord(max) <= ord(b) + 1) { right = left * max; } if (right > b) { right = b; } } for (unsigned long long i = left; i <= right; i += k) { unsigned long long n = i; unsigned long long roots = 0; while (n > 0) { roots += (n % 10) * (n % 10); n /= 10; } if (ord(roots) + ord(k) <= ord(b) + 1) { if (roots * k == i) { sum++; } } } printf("%llu\n", sum); }
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 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 | #include <cstdio> int ord(unsigned long long n) { int tens = 0; while (n > 0) { tens++; n /= 10; } return tens; } int main() { unsigned long long a, b, k; unsigned long long sum = 0; unsigned long long max = 18 * 81; unsigned long long left, right; scanf("%llu %llu %llu", &k, &a, &b); left = right = b + 1; if ((k >= (a / max)) && (k <= b)) { if (k < a) { left = a - (a % k); if (a % k) { left += k; } } else { left = k; } if (ord(left) + ord(max) <= ord(b) + 1) { right = left * max; } if (right > b) { right = b; } } for (unsigned long long i = left; i <= right; i += k) { unsigned long long n = i; unsigned long long roots = 0; while (n > 0) { roots += (n % 10) * (n % 10); n /= 10; } if (ord(roots) + ord(k) <= ord(b) + 1) { if (roots * k == i) { sum++; } } } printf("%llu\n", sum); } |