#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; } |
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