Buggy python submission (verdict: Runtime Error):
import sys
sys.setrecursionlimit(10**8)
def ii(): return int(sys.stdin.readline())
def mi(): return map(int, sys.stdin.readline().split())
def li(): return list(map(int, sys.stdin.readline().split()))
def li2(N): return [list(map(int, sys.stdin.readline().split())) for i in range(N)]
def dp2(ini, i, j): return [[ini]*i for i2 in range(j)]
def dp3(ini, i, j, k): return [[[ini]*i for i2 in range(j)] for i3 in range(k)]
#import bisect #bisect.bisect_left(B, a)
#from collections import defaultdict #d = defaultdict(int) d[key] += value

def rec(i, j, k):
    global dp
    if dp[i][j][k] != -1.0:
        return dp[i][j][k]
    if i+j+k == 0:
        return 0.0

    num = i+j+k
    ans = N_f / num
    if i > 0:
        ans += (rec(i-1, j, k) * i) / num
    if j > 0:
        ans += (rec(i+1, j-1, k) * j) / num
    if k > 0:
        ans += (rec(i, j+1, k-1) * k) / num
    dp[i][j][k] = ans
    return ans

N = ii()
N_f = float(N)
A = li()

cnt = [0, 0, 0]
for a in A:
    cnt[a-1] += 1

dp = dp3(-1.0, cnt[2]+1, cnt[1]+cnt[2]+1, N+1)
dp[0][0][0] = 0

print(rec(cnt[0], cnt[1], cnt[2]))

Fixed submission:
N = int(input())
H = list(map(int, input().split()))

dp = [0]*N

dp[1] = abs(H[1]-H[0])
for i in range(2, N):
    dp[i] =  min(dp[i-2]+abs(H[i]-H[i-2]), dp[i-1]+abs(H[i]-H[i-1]))

print(dp[N-1])

Buggy python submission (verdict: Runtime Error):
import sys
def ii(): return int(sys.stdin.readline())
def mi(): return map(int, sys.stdin.readline().split())
def li(): return list(map(int, sys.stdin.readline().split()))
def li2(N): return [list(map(int, sys.stdin.readline().split())) for i in range(N)]
def dp2(ini, i, j): return [[ini]*i for i2 in range(j)]
def dp3(ini, i, j, k): return [[[ini]*i for i2 in range(j)] for i3 in range(k)]
#import bisect #bisect.bisect_left(B, a)
#from collections import defaultdict #d = defaultdict(int) d[key] += value

from collections import deque
sys.setrecursionlimit(10**6)

N, M = mi()
x = li2(M)

adj = [[] for i in range(N)]
for i in range(M):
    x[i][0] -= 1
    x[i][1] -= 1
    adj[x[i][0]].append(x[i][1])

flag = [0]*N
ans = deque([])

def dfs(x):
    if flag[x]:
        return None
    else:
        flag[x] = 1
        for a in adj[x]:
            dfs(a)
        global ans
        ans.appendleft(x)

for i in range(N):
    dfs(i)

dp = [0]*N
for a in ans:
    for b in adj[a]:
        dp[b] = max(dp[b], dp[a] + 1)

print(max(dp))

Fixed submission:
N = int(input())
H = list(map(int, input().split()))

dp = [0]*N

dp[1] = abs(H[1]-H[0])
for i in range(2, N):
    dp[i] =  min(dp[i-2]+abs(H[i]-H[i-2]), dp[i-1]+abs(H[i]-H[i-1]))

print(dp[N-1])

Buggy python submission (verdict: Runtime Error):
import sys

N, W = map(int, input().split())
WV = [list(map(int, sys.stdin.readline().split())) for i in range(N)]
'''
w = [0]*N
v = [0]*N
for i in range(N):
        w[i], v[i] = map(int, sys.stdin.readline().split())
'''
INF = 10**11+1
dp = [[INF]*(N+1) for j in range(N*(10**3)+10)]
i = 0
ans = INF
while(True):
        for j in range(1, N+1):
                #print(i, j)
                w = WV[j-1][1]
                if i-w >= 0:
                        dp[i][j] = min(dp[i][j-1], dp[i-w][j-1]+WV[j-1][0])
                        #dp[i][j] = max(dp[i-WV[j-1][0]][j-1]+WV[j-1][1], dp[i][j-1])
                else:
                        dp[i][j] = min(dp[i][j-1], WV[j-1][0])
        #print(dp[i][N])
        #print(i, dp[i][N])
        if dp[i][N] > W and ans <= W:
                print(i)
                exit()
        ans = dp[i][N]
        '''
        if dp[i][N] >= W:
                if ans == 0:
                        ans = dp[i][N]
                elif ans < dp[i][N]:
                        print(i)
                        exit()
                print(i, ans)
        '''
        i += 1

Fixed submission:
N = int(input())
H = list(map(int, input().split()))

dp = [0]*N

dp[1] = abs(H[1]-H[0])
for i in range(2, N):
    dp[i] =  min(dp[i-2]+abs(H[i]-H[i-2]), dp[i-1]+abs(H[i]-H[i-1]))

print(dp[N-1])

Buggy python submission (verdict: Runtime Error):
import sys
 
def main():
  N, W = map(int, input().split())
  w = [0]*N
  v = [0]*N
  for i in range(N):
          w[i], v[i] = map(int, sys.stdin.readline().split())

  #WV = [list(map(int, sys.stdin.readline().split())) for i in range(N)]


  dp = [[0]*(N+1) for j in range(W+1)]

  for i in range(1, W+1):
          for j in range(1, N+1):
                  if i - w[j-1]>=0:
                  #if i - WV[j-1][0]>=0:
                          dp[i][j] = max(dp[i-w[j-1]][j-1]+v[j-1], dp[i][j-1])
                          #dp[i][j] = max(dp[i-WV[j-1][0]][j-1]+WV[j-1][1], dp[i][j-1])
                  else:
                          dp[i][j] = dp[i][j-1]

  print(dp[W][N])

if __name__ == '__main__':
    main()

Fixed submission:
N = int(input())
H = list(map(int, input().split()))

dp = [0]*N

dp[1] = abs(H[1]-H[0])
for i in range(2, N):
    dp[i] =  min(dp[i-2]+abs(H[i]-H[i-2]), dp[i-1]+abs(H[i]-H[i-1]))

print(dp[N-1])