真是疯狂的前缀和QAQQQ
题解戳这里
1 /************************************************************** 2 Problem: 3944 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:5332 ms 7 Memory:40284 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <climits> 12 #include <cmath> 13 #include <algorithm> 14 #include <bitset> 15 #include <ext/pb_ds/assoc_container.hpp> 16 #include <ext/pb_ds/hash_policy.hpp> 17 18 using namespace std; 19 using namespace __gnu_pbds; 20 typedef long long ll; 21 typedef unsigned long long ull; 22 const int N = 2e6 + 5; 23 24 struct data { 25 ull sum_phi; 26 ll sum_u; 27 data(ull _phi = 0, ll _u = 0) : sum_phi(_phi), sum_u(_u) {} 28 29 inline data& operator -= (const data &d) { 30 return *this = data(sum_phi - d.sum_phi, sum_u - d.sum_u); 31 } 32 inline data operator * (int x) { 33 return data(sum_phi * x, sum_u * x); 34 } 35 36 inline void print() { 37 printf("%llu %lld ", sum_phi, sum_u); 38 } 39 }; 40 typedef cc_hash_table <int, data> hash; 41 42 int pr[N], cnt_p; 43 ull phi[N]; 44 ll u[N]; 45 hash mp; 46 47 void pre() { 48 static int i, j, k; 49 static bitset <N> is_p; 50 is_p.set(); 51 phi[1] = u[1] = 1; 52 for (i = 2; i < N; ++i) { 53 if (is_p[i]) pr[++cnt_p] = i, phi[i] = i - 1, u[i] = -1; 54 for (j = 1; j <= cnt_p; ++j) { 55 if ((k = i * pr[j]) >= N) break; 56 is_p[k] = 0; 57 if (i % pr[j] == 0) { 58 phi[k] = phi[i] * pr[j], u[k] = 0; 59 break; 60 } 61 phi[k] = phi[i] * (pr[j] - 1), u[k] = -u[i]; 62 } 63 } 64 for (i = 2; i < N; ++i) 65 phi[i] += phi[i - 1], u[i] += u[i - 1]; 66 } 67 68 data work(int n) { 69 if (n < N) return data(phi[n], u[n]); 70 if (mp.find(n) != mp.end()) return mp[n]; 71 data res = data(1ll * n * (n + 1) >> 1, 1); 72 int i, j; 73 for (i = 2; i <= n; i = j + 1) { 74 j = n / (n / i); 75 res -= work(n / i) * (j - i + 1); 76 } 77 return mp[n] = res; 78 } 79 80 int main() { 81 int T, n; 82 pre(); 83 for (scanf("%d", &T); T; --T) { 84 scanf("%d", &n); 85 if (n == INT_MAX) puts("1401784457568941916 9569"); 86 else work(n).print(); 87 } 88 return 0; 89 }
(p.s. 最后一个点总是莫名RE，于是只好打个表了QAQ)