Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
#from numba import njit


#@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Fixed submission:
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1

    expv = np.array([[[-1.0] * (sushi_count[3]+1) for i in range(N-sushi_count[1]+1)] for i in range(N+1)])

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Fixed submission:
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
from numba import njit

N = int(input())

sushi_count = {1:0, 2:0, 3:0}
for a in map(int, input().split()):
    sushi_count[a] += 1

expv = np.array([[[-1.0] * (sushi_count[3]+1) for i in range(N-sushi_count[1]+1)] for i in range(N+1)])

expv[0][0][0] = 0.0

@njit('f8(i8,i8,i8,f8[:,:,:])')
def get_expv(i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

print(get_expv(sushi_count[1], sushi_count[2], sushi_count[3], expv))



Fixed submission:
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
from numba import njit

N = int(input())

sushi_count = {1:0, 2:0, 3:0}
for a in map(int, input().split()):
    sushi_count[a] += 1

expv = np.array([[[-1.0] * (sushi_count[3]+1) for i in range(N-sushi_count[1]+1)] for i in range(N+1)])

expv[0][0][0] = 0.0

def get_expv(i, j, k):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(i-1, j, k) * (i / N)
    if j != 0:
        result += get_expv(i+1, j-1, k) * (j / N)
    if k != 0:
        result += get_expv(i, j+1, k-1) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

print(get_expv(sushi_count[1], sushi_count[2], sushi_count[3]))



Fixed submission:
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np
from numba import njit

N = int(input())

sushi_count = {1:0, 2:0, 3:0}
for a in map(int, input().split()):
    sushi_count[a] += 1

expv = np.array([[[-1.0] * (sushi_count[3]+1) for i in range(N-sushi_count[1]+1)] for i in range(N+1)])

expv[0][0][0] = 0.0

@njit
def get_expv(i, j, k):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(i-1, j, k) * (i / N)
    if j != 0:
        result += get_expv(i+1, j-1, k) * (j / N)
    if k != 0:
        result += get_expv(i, j+1, k-1) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

print(get_expv(sushi_count[1], sushi_count[2], sushi_count[3]))

Fixed submission:
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
'''
expv[i][j][k] = 1 +
                expv[i-1][j][k] * (i / N) +
                expv[i+1][j-1][k] * (j / N) +
                expv[i][j+1][k-1] * (k / N) + 
                expv[i][j][k] * ((N - i - j - k) / N)

nonlp = 1 - (N-i-j-k) / N 
expv[i][j][k] =  (1 + ~~) / nonlp

'''

N = int(input())

sushi_count = {1:0, 2:0, 3:0}
for a in map(int, input().split()):
    sushi_count[a] += 1

expv = [[[-1] * (sushi_count[3]+1) for i in range(N-sushi_count[1]+1)] for i in range(N+1)]

expv[0][0][0] = 0.0

def get_expv(i, j, k):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(i-1, j, k) * (i / N)
    if j != 0:
        result += get_expv(i+1, j-1, k) * (j / N)
    if k != 0:
        result += get_expv(i, j+1, k-1) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

print(get_expv(sushi_count[1], sushi_count[2], sushi_count[3]))


Fixed submission:
import numpy as np
from numba import njit


@njit('f8(i8,i8,i8,i8,f8[:,:,:])')
def get_expv(N, i, j, k, expv):
    result = 0.0
    if expv[i][j][k] != -1:
        return expv[i][j][k]
    nonlp = 1.0 - (N-i-j-k) / N
    result += 1
    if i != 0:
        result += get_expv(N, i-1, j, k, expv) * (i / N)
    if j != 0:
        result += get_expv(N, i+1, j-1, k, expv) * (j / N)
    if k != 0:
        result += get_expv(N, i, j+1, k-1, expv) * (k / N)
    result /= nonlp
    expv[i][j][k] = result
    return result

def main():
    N = int(input())

    sushi_count = {1:0, 2:0, 3:0}
    for a in map(int, input().split()):
        sushi_count[a] += 1
    sh = (N+1, N-sushi_count[1]+1, sushi_count[3]+1)
    expv = np.full(sh, -1.0)

    expv[0][0][0] = 0.0

    print(get_expv(N, sushi_count[1], sushi_count[2], sushi_count[3], expv))

if __name__ == '__main__':
    main()