#include <algorithm> #include <cstdio> #include <map> #include <tuple> #include <vector> using namespace std; void print_vector(vector<int> v) { for (int i = 0; i < v.size(); i++) { printf("%d ", v[i]); } puts(""); } bool is_square[25100000]; bool is_sum_of_squares[25100000]; vector<int> squares; int values[25100000]; void init(int n) { for (int i = 0; i <= n * n; i++) { is_square[i] = false; is_sum_of_squares[i] = false; values[i] = 0; } int i = 1; while (i * i <= n * n) { squares.push_back(i * i); is_square[i * i] = true; i++; } } int main() { int n; scanf("%d", &n); init(n); for (int i = 0; i < squares.size(); i++) { for (int j = 0; j < squares.size(); j++) { int temp = squares[i] - squares[j]; if (temp > 0) { // printf("%d\n", temp); values[temp]++; } else { break; } } } long long result = 0; for (int i = 0; i < squares.size(); i++) { for (int j = i; j < squares.size(); j++) { long long sum = squares[i] + squares[j]; // printf("%d %d %d\n", squares[i], squares[j], values[sum]); if (sum <= n * n) { result += values[sum]; } } } printf("%lld\n", 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 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 | #include <algorithm> #include <cstdio> #include <map> #include <tuple> #include <vector> using namespace std; void print_vector(vector<int> v) { for (int i = 0; i < v.size(); i++) { printf("%d ", v[i]); } puts(""); } bool is_square[25100000]; bool is_sum_of_squares[25100000]; vector<int> squares; int values[25100000]; void init(int n) { for (int i = 0; i <= n * n; i++) { is_square[i] = false; is_sum_of_squares[i] = false; values[i] = 0; } int i = 1; while (i * i <= n * n) { squares.push_back(i * i); is_square[i * i] = true; i++; } } int main() { int n; scanf("%d", &n); init(n); for (int i = 0; i < squares.size(); i++) { for (int j = 0; j < squares.size(); j++) { int temp = squares[i] - squares[j]; if (temp > 0) { // printf("%d\n", temp); values[temp]++; } else { break; } } } long long result = 0; for (int i = 0; i < squares.size(); i++) { for (int j = i; j < squares.size(); j++) { long long sum = squares[i] + squares[j]; // printf("%d %d %d\n", squares[i], squares[j], values[sum]); if (sum <= n * n) { result += values[sum]; } } } printf("%lld\n", result); return 0; } |