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

read= sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
MOD = 1000000007
sys.setrecursionlimit(10**7)

#N,*A = map(int,read().split())
N = int(input())
A = list(map(int,input().split()))



#増減のメモ 
# A[i] > A[i+1]  :  1
# A[i] < A[i+1]  : -1
# A[i] == A[i+1] :  0
x = []
for i in range(N-1):
    if A[i]  < A[i+1]:
        x.append(1)
    elif A[i] > A[i+1]:
        x.append(-1)
    else:
        x.append(0)


res = 1  #答え

#print(len(x))
state = x[0] #単調増加 or 単調減少の二種で現在の状態を記録
i = 1
while  i < N-1:
    if x[i] ==  state or state == 0:
        pass
    else:
        if i != N -2:
            state = x[i+1]
            i+=1
            res+=1
    i+=1

if x[-1] != x[-2] and x[-1] != 0 and x[-2]!= 0 :
    print(res+1)
else:
    print(res)


Fixed submission:
import sys

read= sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
MOD = 1000000007
sys.setrecursionlimit(10**7)

#N,*A = map(int,read().split())
N = int(input())
l = list(map(int,input().split()))

#最初の状態分を加算するため、1からカウント
ans = 1

S = 0 #現在の状態 増加 or 減少 or 初期化

for i in range(1,N):
    X = l[i] - l[i-1]

    X = 0 if X == 0 else 1 if X > 0 else -1

    #同じ値の時l[i] == l[i-1]
    if X == 0:
        continue

    #Stateが初期のときは現在の状態に更新
    elif S == 0:
        S = X

    #Stateが違うときは答えに加算して、Stateを初期値に
    elif S != X:
        ans += 1
        S = 0

print(ans)

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

read= sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
MOD = 1000000007
sys.setrecursionlimit(10**7)

N = int(readline())
A = list(map(int,readline().split()))

res = 0

in_i = 0
de_i = 0
i = 0
while i < N-1:
    for j in range(i+1,N):
        if A[j] >= A[j-1]:continue
        else:
            break

    in_i = j
    for j in range(i+1,N):
        if A[j] <= A[j-1]:continue
        else:
            break
    de_i = j

    i = max(de_i,in_i)
    res+=1
#print(res)

if (A[-3] - A[-2])*(A[-2] - A[-1]) >= 0: print(res)
else: print(res+1)

Fixed submission:
import sys

read= sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
MOD = 1000000007
sys.setrecursionlimit(10**7)

#N,*A = map(int,read().split())
N = int(input())
l = list(map(int,input().split()))

#最初の状態分を加算するため、1からカウント
ans = 1

S = 0 #現在の状態 増加 or 減少 or 初期化

for i in range(1,N):
    X = l[i] - l[i-1]

    X = 0 if X == 0 else 1 if X > 0 else -1

    #同じ値の時l[i] == l[i-1]
    if X == 0:
        continue

    #Stateが初期のときは現在の状態に更新
    elif S == 0:
        S = X

    #Stateが違うときは答えに加算して、Stateを初期値に
    elif S != X:
        ans += 1
        S = 0

print(ans)

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

read= sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
MOD = 1000000007
sys.setrecursionlimit(10**7)

N = int(readline())
A = list(map(int,readline().split()))

res = 0

in_i = 0
de_i = 0
i = 0
while i <= N-1:
    for j in range(i+1,N):
        if A[j] >= A[j-1]:continue
        else:
            break

    in_i = j
    for j in range(i+1,N):
        if A[j] <= A[j-1]:continue
        else:
            break
    de_i = j

    i = max(de_i,in_i)
    res+=1
print(i)

print(res)



Fixed submission:
import sys

read= sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
MOD = 1000000007
sys.setrecursionlimit(10**7)

#N,*A = map(int,read().split())
N = int(input())
l = list(map(int,input().split()))

#最初の状態分を加算するため、1からカウント
ans = 1

S = 0 #現在の状態 増加 or 減少 or 初期化

for i in range(1,N):
    X = l[i] - l[i-1]

    X = 0 if X == 0 else 1 if X > 0 else -1

    #同じ値の時l[i] == l[i-1]
    if X == 0:
        continue

    #Stateが初期のときは現在の状態に更新
    elif S == 0:
        S = X

    #Stateが違うときは答えに加算して、Stateを初期値に
    elif S != X:
        ans += 1
        S = 0

print(ans)