#include <bits/stdc++.h> using namespace std; using ll = long long; // count pairs (k, l) such that k + kl = m and k, l > 1 ll count2(int m) { ll res = 0; for (int k = 2; k * k <= m; k++) { if (m % k == 0) { if (m / k >= 3) { res++; } if (k * k != m && k >= 3) { res++; } } } return res; } // #(a, b, c) such that a < b < c, a + b + c = n and // (a, b, c) = (a, ka, lka) ll solve(int n) { ll res = 0; for (int a = 1; a * a <= n; a++) { if (n % a == 0) { res += count2(n / a - 1); if (a * a != n) { res += count2(a - 1); } } } return res; } int main() { ios_base::sync_with_stdio(false); int n; cin >> n; cout << solve(n) << "\n"; }
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 | #include <bits/stdc++.h> using namespace std; using ll = long long; // count pairs (k, l) such that k + kl = m and k, l > 1 ll count2(int m) { ll res = 0; for (int k = 2; k * k <= m; k++) { if (m % k == 0) { if (m / k >= 3) { res++; } if (k * k != m && k >= 3) { res++; } } } return res; } // #(a, b, c) such that a < b < c, a + b + c = n and // (a, b, c) = (a, ka, lka) ll solve(int n) { ll res = 0; for (int a = 1; a * a <= n; a++) { if (n % a == 0) { res += count2(n / a - 1); if (a * a != n) { res += count2(a - 1); } } } return res; } int main() { ios_base::sync_with_stdio(false); int n; cin >> n; cout << solve(n) << "\n"; } |