题意
给出一些数字,对于每个数字找到一个欧拉函数值大于等于这个数的数,求找到的所有数的最小和。
Solution
线性筛出phi,把询问数组排序搞就行了
# include# define RG register# define IL inline# define Fill(a, b) memset(a, b, sizeof(a))using namespace std;typedef long long ll;const int _(1e4 + 10), __(1e6 + 10);IL ll Read(){ char c = '%'; ll x = 0, z = 1; for(; c > '9' || c < '0'; c = getchar()) if(c == '-') z = -1; for(; c >= '0' && c <= '9'; c = getchar()) x = x * 10 + c - '0'; return x * z;}int n, a[_], id[_], prime[__], isprime[__], num, phi[__];ll ans;IL void Prepare(){ for(RG int i = 2; i <= __; ++i){ if(!isprime[i]) prime[++num] = i, phi[i] = i - 1; for(RG int j = 1; j <= num && i * prime[j] <= __; ++j){ isprime[i * prime[j]] = 1; if(!(i % prime[j])){ phi[i * prime[j]] = phi[i] * prime[j]; break; } else phi[i * prime[j]] = phi[i] * (prime[j] - 1); } }}int main(RG int argc, RG char *argv[]){ Prepare(); for(RG int T = Read(), i = 1; i <= T; ++i){ n = Read(); ans = 0; for(RG int j = 1; j <= n; ++j) a[j] = Read(); sort(a + 1, a + n + 1); for(RG int j = 1, l = 1; j <= n; ++j){ while(phi[l] < a[j]) ++l; ans += l; } printf("Case %d: %lld Xukha\n", i, ans); } return 0;}