#include #include #include #include #include #include #include #include #include // require sort next_permutation count __gcd reverse etc. #include // require abs exit atof atoi #include // require scanf printf #include #include // require accumulate #include // require fabs #include #include #include #include // require setw #include // require stringstream #include // require memset #include // require tolower, toupper #include // require freopen #include // require srand #define rep(i,n) for(int i=0;i<(n);i++) #define ALL(A) A.begin(), A.end() using namespace std; typedef long long ll; /* No.76 回数の期待値で練習 条件付期待値 定理 E[N] = E[E[N|Y]] E[N|Y] = Σ E[N|Y=i]P(Y=i) E[N]: N 以上になるまでに振る回数の期待値 Y: 直前に振ったサイコロの目(=1,2,3,4,5,6) E[N|Y]: 直前に振ったサイコロの目が Y の場合の N 以上になるまでに振る回数の期待値 E[N] = E[N|Y=1]*P1 + E[N|Y=2]*P2 + E[N|Y=3]*P3 + E[N|Y=4]*P4 + E[N|Y=5]*P5 + E[N|Y=6]*P6 (ただし P(Y=i) = Pi と置いた) N = 1 のとき E[1] = E[1|Y=1]*P1 + E[1|Y=2]*P2 + E[1|Y=3]*P3 + E[1|Y=4]*P4 + E[1|Y=5]*P5 + E[1|Y=6]*P6 = 1*P1 + 1*P2 + 1*P3 + 1*P4 + 1*P5 + 1*P6 = 1 N = 2 のとき E[2] = E[2|Y=1]*P1 + E[2|Y=2]*P2 + E[2|Y=3]*P3 + E[2|Y=4]*P4 + E[2|Y=5]*P5 + E[2|Y=6]*P6 = (1 + E[1])*P1 + 1*P2 + 1*P3 + 1*P4 + 1*P5 + 1*P6 = E[1]*P1 + 1 N = 3 のとき E[3] = E[3|Y=1]*P1 + E[3|Y=2]*P2 + E[3|Y=3]*P3 + E[3|Y=4]*P4 + E[3|Y=5]*P5 + E[3|Y=6]*P6 = (1 + E[2])*P1 + (1 + E[1])*P2 + 1*P3 + 1*P4 + 1*P5 + 1*P6 = E[2]*P1 + E[1]*P2 + 1 N = 4 のとき E[4] = E[4|Y=1]*P1 + E[4|Y=2]*P2 + E[4|Y=3]*P3 + E[4|Y=4]*P4 + E[4|Y=5]*P5 + E[4|Y=6]*P6 = (1 + E[3])*P1 + (1 + E[2])*P2 + (1 + E[1])*P3 + 1*P4 + 1*P5 + 1*P6 = E[3]*P1 + E[2]*P2 + E[1]*P3 + 1 N = 5 のとき E[5] = E[5|Y=1]*P1 + E[5|Y=2]*P2 + E[5|Y=3]*P3 + E[5|Y=4]*P4 + E[5|Y=5]*P5 + E[5|Y=6]*P6 = (1 + E[4])*P1 + (1 + E[3])*P2 + (1 + E[2])*P3 + (1 + E[1])*P4 + 1*P5 + 1*P6 = E[4]*P1 + E[3]*P2 + E[2]*P3 + E[1]*P4 + 1 N = 6 のとき E[6] = E[6|Y=1]*P1 + E[6|Y=2]*P2 + E[6|Y=3]*P3 + E[6|Y=4]*P4 + E[6|Y=5]*P5 + E[6|Y=6]*P6 = (1 + E[5])*P1 + (1 + E[4])*P2 + (1 + E[3])*P3 + (1 + E[2])*P4 + (1 + E[1])*P5 + 1*P6 = E[5]*P1 + E[4]*P2 + E[3]*P3 + E[2]*P4 + E[1]*P5 + 1 N = 7 のとき E[7] = E[7|Y=1]*P1 + E[7|Y=2]*P2 + E[7|Y=3]*P3 + E[7|Y=4]*P4 + E[7|Y=5]*P5 + E[7|Y=6]*P6 = (1 + E[6])*P1 + (1 + E[5])*P2 + (1 + E[4])*P3 + (1 + E[3])*P4 + (1 + E[2])*P5 + (1 + E[1])*P6 = E[6]*P1 + E[5]*P2 + E[4]*P3 + E[3]*P4 + E[2]*P5 + E[1]*P6 + 1 N > 7 のとき E[i+7] = E[i+7|Y=1]*P1 + E[i+7|Y=2]*P2 + E[i+7|Y=3]*P3 + E[i+7|Y=4]*P4 + E[i+7|Y=5]*P5 + E[i+7|Y=6]*P6 = (1 + E[i+6])*P1 + (1 + E[i+5])*P2 + (1 + E[i+4])*P3 + (1 + E[i+3])*P4 + (1 + E[i+2])*P5 + (1 + E[i+1])*P6 = E[i+6]*P1 + E[i+5]*P2 + E[i+4]*P3 + E[i+3]*P4 + E[i+2]*P5 + E[i+1]*P6 + 1 */ const int MAX_N = (int)1e6 + 6; const double E[7] = { 0, 1.0000000000000000, 1.0833333333333333, 1.2569444444444444 ,1.5353009259259260, 1.6915991512345676, 2.0513639724794235 }; double P[7]; double dp[MAX_N]; int main() { memset (P, 0., sizeof (P ) ); memset (dp, 0., sizeof (dp ) ); ios_base::sync_with_stdio(0); P[1] = (E[2] - 1. )/E[1]; P[2] = (E[3] - E[2]*P[1] - 1. )/E[1]; P[3] = (E[4] - E[3]*P[1] - E[2]*P[2] - 1. )/E[1]; P[4] = (E[5] - E[4]*P[1] - E[3]*P[2] - E[2]*P[3] - 1. )/E[1]; P[5] = (E[6] - E[5]*P[1] - E[4]*P[2] - E[3]*P[3] - E[2]*P[4] - 1. )/E[1]; P[6] = 1. - P[1] - P[2] - P[3] - P[4] - P[5] - P[6]; for (int i = 1; i <= 6; i++ ) dp[i] = E[i]; for (int i = 7; i < MAX_N; i++ ){ for (int j = 1; j <= 6; j++ ){ dp[i] += dp[i-j]*P[j]; } // end for dp[i] += 1.; } // end for int T; cin >> T; while (T-- ){ int Nk; cin >> Nk; printf ("%.8lf\n", dp[Nk] ); } // end while return 0; }