Buggy python submission (verdict: Time Limit Exceeded):
def longest_common_subsequence(S, T):
    LS = len(S); LT = len(T)
    dp = [[0] * (LT + 1) for _ in range(LS + 1)]
    for i, s in enumerate(S):
        for j, t in enumerate(T):
            if s == t:
                dp[i + 1][j + 1] = dp[i][j] + 1
            else:
                dp[i + 1][j + 1] = max(dp[i][j + 1], dp[i + 1][j])
    return dp
    

def reconstruct_LCS(S, T, dp):
    tmp = []
    i, j = len(S), len(T)
    while i and j:
        if S[i - 1] == T[j - 1]:
            i, j = i - 1, j - 1
            tmp.append(S[i])
        elif dp[i][j] == dp[i - 1][j]:
            i -= 1
        else:
            j -= 1
    return ''.join(reversed(tmp))


s,t=input(), input()
print(reconstruct_LCS(s, t, longest_common_subsequence(s, t)))


Fixed submission:
s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for i in range(m+1)] for j in range(n+1)]
for i in range(n):
    for j in range(m):
        if s[i]==t[j]:
            dp[i+1][j+1]=dp[i][j]+1
        else:
            dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
ans = ''
while(dp[n][m]>0):
  if dp[n][m] == dp[n-1][m-1] +1 and dp[n][m] == dp[n-1][m] +1 and dp[n][m] == dp[n][m-1] +1:
    ans = ''.join([s[n-1],ans])
    n -= 1
    m -= 1
  elif dp[n-1][m] > dp[n][m-1]:
    n -= 1
  else:
    m -= 1
print(ans)

Buggy python submission (verdict: Runtime Error):
def longest_common_subsequence(S, T):
    LS = len(S); LT = len(T)
    dp = [[0] * (LT + 1) for _ in range(LS + 1)]
    for i, s in enumerate(S):
        for j, t in enumerate(T):
            if s == t:
                dp[i + 1][j + 1] = dp[i][j] + 1
            else:
                dp[i + 1][j + 1] = max(dp[i][j + 1], dp[i + 1][j])
    return dp
    

def reconstruct_LCS(S, T, dp):
    tmp = []
    i, j = len(S), len(T)
    while i and j:
        if S[i - 1] == T[j - 1]:
            i, j = i - 1, j - 1
            tmp.append(S[i])
        elif dp[i][j] == dp[i - 1][j]:
            i -= 1
        else:
            j -= 1
    return ''.join(reversed(tmp))


s,t=input(), input()
print(reconstruct_LCS(s, t, LCS(s, t)))


Fixed submission:
s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for i in range(m+1)] for j in range(n+1)]
for i in range(n):
    for j in range(m):
        if s[i]==t[j]:
            dp[i+1][j+1]=dp[i][j]+1
        else:
            dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
ans = ''
while(dp[n][m]>0):
  if dp[n][m] == dp[n-1][m-1] +1 and dp[n][m] == dp[n-1][m] +1 and dp[n][m] == dp[n][m-1] +1:
    ans = ''.join([s[n-1],ans])
    n -= 1
    m -= 1
  elif dp[n-1][m] > dp[n][m-1]:
    n -= 1
  else:
    m -= 1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for i in range(m+1)] for j in range(n+1)]
for i in range(n):
    for j in range(m):
        if s[i]==t[j]:
            dp[i+1][j+1]=dp[i][j]+1
        else:
            dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
ans = ''
while(dp[n][m]>0):
  if dp[n][m] == dp[n-1][m-1] +1 and dp[n][m] == dp[n-1][m] +1 and dp[n][m] == dp[n][m-1] +1:
    ans += s[n-1]
    n -= 1
    m -= 1
  elif dp[n-1][m] > dp[n][m-1]:
    n -= 1
  else:
    m -= 1
print(''.join(reversed(list(ans))))

Fixed submission:
s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for i in range(m+1)] for j in range(n+1)]
for i in range(n):
    for j in range(m):
        if s[i]==t[j]:
            dp[i+1][j+1]=dp[i][j]+1
        else:
            dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
ans = ''
while(dp[n][m]>0):
  if dp[n][m] == dp[n-1][m-1] +1 and dp[n][m] == dp[n-1][m] +1 and dp[n][m] == dp[n][m-1] +1:
    ans = ''.join([s[n-1],ans])
    n -= 1
    m -= 1
  elif dp[n-1][m] > dp[n][m-1]:
    n -= 1
  else:
    m -= 1
print(ans)

Buggy python submission (verdict: Runtime Error):
s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for i in range(m+1)] for j in range(n+1)]
​
​
#メイン
​
#dp[i][j]:=s_1~s_iとt_1~t_jに対するLCSの長さ
for i in range(n):
    for j in range(m):
        if s[i]==t[j]:
            dp[i+1][j+1]=dp[i][j]+1 #同じならくっつけられる
        else:
            dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
#print(dp[n][m])
#dpを逆からたどって文字列を復元
ans = ''
while(dp[n][m]>0):
  if dp[n][m] == dp[n-1][m-1] +1 and dp[n][m] == dp[n-1][m] +1 and dp[n][m] == dp[n][m-1] +1:
    ans += s[n-1]
    n -= 1
    m -= 1
  elif dp[n-1][m] > dp[n][m-1]:
    n -= 1
  else:
    m -= 1
print(''.join(reversed(list(ans))))

Fixed submission:
s=input()
t=input()
n=len(s)
m=len(t)
dp=[[0 for i in range(m+1)] for j in range(n+1)]
for i in range(n):
    for j in range(m):
        if s[i]==t[j]:
            dp[i+1][j+1]=dp[i][j]+1
        else:
            dp[i+1][j+1]=max(dp[i][j+1],dp[i+1][j])
ans = ''
while(dp[n][m]>0):
  if dp[n][m] == dp[n-1][m-1] +1 and dp[n][m] == dp[n-1][m] +1 and dp[n][m] == dp[n][m-1] +1:
    ans = ''.join([s[n-1],ans])
    n -= 1
    m -= 1
  elif dp[n-1][m] > dp[n][m-1]:
    n -= 1
  else:
    m -= 1
print(ans)