Buggy python submission (verdict: Runtime Error):
s = input()
t = input()
n, m = len(s), len(t)
dp = [[0]*(m+1) for _ in range(n+1)]

for i in range(1, n+1):
    for j in range(1, m+1):
        if s[i] == t[j]:
            dp[i][j] = dp[i-1][j-1] + 1
        else:
            dp[i][j] = max(dp[i-1][j], dp[i][j-1])

i, j = n, m

ans = []

while i > 0 and j > 0:
    if dp[i][j] == dp[i][j-1]:
        j -= 1
    elif dp[i][j] == dp[i-1][j]:
        i -= 1
    else:
        ans.append(s[i])
        i -= 1
        j -= 1

print(reversed(ans))

Fixed submission:
s = input()
t = input()
n, m = len(s), len(t)
dp = [[0]*(m+1) for _ in range(n+1)]

for i in range(1, n+1):
    for j in range(1, m+1):
        if s[i-1] == t[j-1]:
            dp[i][j] = dp[i-1][j-1] + 1
        else:
            dp[i][j] = max(dp[i-1][j], dp[i][j-1])

i, j = n, m

ans = []

while i > 0 and j > 0:
    if dp[i][j] == dp[i][j-1]:
        j -= 1
    elif dp[i][j] == dp[i-1][j]:
        i -= 1
    else:
        ans.append(s[i-1])
        i -= 1
        j -= 1

print("".join(reversed(ans)))

Buggy python submission (verdict: Runtime Error):
s = input()
t = input()
n, m = len(s), len(t)
dp = [[0]*(m+1) for _ in range(n+1)]

for i in range(1, n+1):
    for j in range(1, m+1):
        if s[i] == t[j]:
            dp[i][j] = dp[i-1][j-1] + 1
        else:
            dp[i][j] = max(dp[i-1][j], dp[i][j-1])

i, j = n, m

ans = []

while i > 0 and j > 0:
    if dp[i][j] == dp[i][j-1]:
        j -= 1
    elif dp[i][j] == dp[i-1][j]:
        i -= 1
    else:
        ans.append(s[i])
        i -= 1
        j -= 1

print(ans)

Fixed submission:
s = input()
t = input()
n, m = len(s), len(t)
dp = [[0]*(m+1) for _ in range(n+1)]

for i in range(1, n+1):
    for j in range(1, m+1):
        if s[i-1] == t[j-1]:
            dp[i][j] = dp[i-1][j-1] + 1
        else:
            dp[i][j] = max(dp[i-1][j], dp[i][j-1])

i, j = n, m

ans = []

while i > 0 and j > 0:
    if dp[i][j] == dp[i][j-1]:
        j -= 1
    elif dp[i][j] == dp[i-1][j]:
        i -= 1
    else:
        ans.append(s[i-1])
        i -= 1
        j -= 1

print("".join(reversed(ans)))

Buggy python submission (verdict: Runtime Error):
def LCS(s, t):
    res = ''
    m, n = len(s), len(t)

    def rec(cur, i, j):
        nonlocal res, s, t, m, n
        if i == m or j == n:
            res = max(''.join(cur), res, key=len)
            return

        if s[i] == t[j]:
            cur.append(s[i])
            rec(cur, i+1, j+1)
            cur.pop()
        else:
            rec(cur, i+1, j)
            rec(cur, i, j+1)

    rec([], 0, 0)

    return res


if __name__ == '__main__':

    s = input()
    t = input()

    print(LCS(s, t))

Fixed submission:
s = input()
t = input()
n, m = len(s), len(t)
dp = [[0]*(m+1) for _ in range(n+1)]

for i in range(1, n+1):
    for j in range(1, m+1):
        if s[i-1] == t[j-1]:
            dp[i][j] = dp[i-1][j-1] + 1
        else:
            dp[i][j] = max(dp[i-1][j], dp[i][j-1])

i, j = n, m

ans = []

while i > 0 and j > 0:
    if dp[i][j] == dp[i][j-1]:
        j -= 1
    elif dp[i][j] == dp[i-1][j]:
        i -= 1
    else:
        ans.append(s[i-1])
        i -= 1
        j -= 1

print("".join(reversed(ans)))

Buggy python submission (verdict: Runtime Error):
def LCS(s, t):
    res = ''
    m, n = len(s), len(t)

    def rec(cur, i, j):
        nonlocal res, s, t, m, n
        if i == m or j == n:
            res = max(''.join(cur), res, key=len)
            return

        if s[i] == t[j]:
            cur.append(s[i])
            rec(cur, i+1, j+1)
            cur.pop()
        else:
            rec(cur, i+1, j)
            rec(cur, i, j+1)

    rec([], 0, 0)

    return res


s = input()
t = input()

print(LCS(s, t))

Fixed submission:
s = input()
t = input()
n, m = len(s), len(t)
dp = [[0]*(m+1) for _ in range(n+1)]

for i in range(1, n+1):
    for j in range(1, m+1):
        if s[i-1] == t[j-1]:
            dp[i][j] = dp[i-1][j-1] + 1
        else:
            dp[i][j] = max(dp[i-1][j], dp[i][j-1])

i, j = n, m

ans = []

while i > 0 and j > 0:
    if dp[i][j] == dp[i][j-1]:
        j -= 1
    elif dp[i][j] == dp[i-1][j]:
        i -= 1
    else:
        ans.append(s[i-1])
        i -= 1
        j -= 1

print("".join(reversed(ans)))