下面count_triple函数的时间复杂度为( )。
int count_triple(int n) { int cnt = 0; for (int a = 1; a <= n; a++) for (int b = a; a + b <= n; b++) for (int c = b; a + b + c <= n; c++) if (a * a + b * b == c * c) cnt++; return cnt; }