#include <iostream> using namespace std; const unsigned long long maxf = 9 * 9 * 18; int powers[] = {0, 1, 4, 9, 16, 25, 36, 49, 64, 81}; unsigned long long f(unsigned long long n) { unsigned long long sum = 0; while (n) { unsigned int dig = n % 10; sum += powers[dig]; n /= 10; } return sum; } int main() { unsigned long long k, a, b; cin >> k >> a >> b; unsigned long long result = 0; for (unsigned long long i = a; i <= b; ++i) { if (i % k != 0) continue; if (i > k * maxf) break; if (i == k * f(i)) { ++result; } } cout << result; 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 31 32 33 34 35 36 37 38 39 40 41 42 43 | #include <iostream> using namespace std; const unsigned long long maxf = 9 * 9 * 18; int powers[] = {0, 1, 4, 9, 16, 25, 36, 49, 64, 81}; unsigned long long f(unsigned long long n) { unsigned long long sum = 0; while (n) { unsigned int dig = n % 10; sum += powers[dig]; n /= 10; } return sum; } int main() { unsigned long long k, a, b; cin >> k >> a >> b; unsigned long long result = 0; for (unsigned long long i = a; i <= b; ++i) { if (i % k != 0) continue; if (i > k * maxf) break; if (i == k * f(i)) { ++result; } } cout << result; return 0; } |